Guide to the Secure Configuration of Ubuntu 22.04

This guide presents a catalog of security-relevant configuration settings for Ubuntu 22.04. It is a rendering of content structured in the eXtensible Configuration Checklist Description Format (XCCDF) in order to support security automation. The SCAP content is is available in the scap-security-guide package which is developed at https://www.open-scap.org/security-policies/scap-security-guide.

Providing system administrators with such guidance informs them how to securely configure systems under their control in a variety of network roles. Policy makers and baseline creators can use this catalog of settings, with its associated references to higher-level security control catalogs, in order to assist them in security baseline creation. This guide is a catalog, not a checklist, and satisfaction of every item is not likely to be possible or sensible in many operational scenarios. However, the XCCDF format enables granular selection and adjustment of settings, and their association with OVAL and OCIL content provides an automated checking capability. Transformations of this document, and its associated automated checking content, are capable of providing baselines that meet a diverse set of policy objectives. Some example XCCDF Profiles, which are selections of items that form checklists and can be used as baselines, are available with this guide. They can be processed, in an automated fashion, with tools that support the Security Content Automation Protocol (SCAP). The DISA STIG, which provides required settings for US Department of Defense systems, is one example of a baseline created from this guidance.
Do not attempt to implement any of the settings in this guide without first testing them in a non-operational environment. The creators of this guidance assume no responsibility whatsoever for its use by other parties, and makes no guarantees, expressed or implied, about its quality, reliability, or any other characteristic.

Evaluation Characteristics

Evaluation targetjuju-ae5712-0
Benchmark URL/usr/share/ubuntu-scap-security-guides/current/benchmarks/ssg-ubuntu2204-xccdf.xml
Benchmark IDxccdf_org.ssgproject.content_benchmark_UBUNTU_22-04
Profile IDxccdf_org.ssgproject.content_profile_cis_level1_server_customized
Started at2024-04-05T12:58:22
Finished at2024-04-05T12:59:33
Performed byubuntu

CPE Platforms

  • cpe:/o:canonical:ubuntu_linux:22.04::~~lts~~~

Addresses

  • IPv4  127.0.0.1
  • IPv4  10.244.164.218
  • IPv6  0:0:0:0:0:0:0:1
  • IPv6  fd42:2d0:9dd7:d7c5:216:3eff:fe65:3d45
  • IPv6  fe80:0:0:0:216:3eff:fe65:3d45
  • MAC  00:00:00:00:00:00
  • MAC  00:16:3E:65:3D:45

Compliance and Scoring

There were no failed rules, but the results of 4 rules were inconclusive! Please review rule results and consider applying remediation.

Rule results

226 passed
0 failed
4 other

Severity of failed rules

0 other
0 low
0 medium
0 high

Score

Scoring systemScoreMaximumPercent
urn:xccdf:scoring:default97.976852100.000000
97.98%

Rule Overview

Group rules by:
TitleSeverityResult
Guide to the Secure Configuration of Ubuntu 22.04 4x unknown
System Settings 3x unknown
Installing and Maintaining Software
System and Software Integrity
Software Integrity Checking
Verify Integrity with AIDE
Install AIDEmedium
pass
Build and Test AIDE Databasemedium
pass
Configure AIDE to Verify the Audit Toolsmedium
pass
Configure Periodic Execution of AIDEmedium
pass
GNOME Desktop Environment
Disable the GNOME3 Login User Listmedium
notapplicable
Disable XDMCP in GDMhigh
notapplicable
GNOME Media Settings
Disable GNOME3 Automountingmedium
notapplicable
Disable GNOME3 Automount Openingmedium
notapplicable
Disable GNOME3 Automount runninglow
notapplicable
Configure GNOME Screen Locking
Set GNOME3 Screensaver Lock Delay After Activation Periodmedium
notapplicable
Enable GNOME3 Screensaver Lock After Idle Periodmedium
notapplicable
Sudo
Install sudo Packagemedium
pass
Ensure Only Users Logged In To Real tty Can Execute Sudo - sudo use_ptymedium
pass
Ensure Sudo Logfile Exists - sudo logfilelow
pass
Ensure Users Re-Authenticate for Privilege Escalation - sudo !authenticatemedium
pass
Require Re-Authentication When Using the sudo Commandmedium
pass
Account and Access Control
Warning Banners for System Accesses
Enable GNOME3 Login Warning Bannermedium
notapplicable
Modify the System Login Bannermedium
pass
Modify the System Login Banner for Remote Connectionsmedium
pass
Modify the System Message of the Day Bannermedium
pass
Verify Group Ownership of System Login Bannermedium
pass
Verify Group Ownership of System Login Banner for Remote Connectionsmedium
pass
Verify Group Ownership of Message of the Day Bannermedium
pass
Verify ownership of System Login Bannermedium
pass
Verify ownership of System Login Banner for Remote Connectionsmedium
pass
Verify ownership of Message of the Day Bannermedium
pass
Verify permissions on System Login Bannermedium
pass
Verify permissions on System Login Banner for Remote Connectionsmedium
pass
Verify permissions on Message of the Day Bannermedium
pass
Protect Accounts by Configuring PAM
Set Lockouts for Failed Password Attempts
Limit Password Reusemedium
pass
Lock Accounts After Failed Password Attemptsmedium
pass
Set Interval For Counting Failed Password Attemptsmedium
pass
Set Lockout Time for Failed Password Attemptsmedium
pass
Set Password Quality Requirements
Set Password Quality Requirements with pam_pwquality
Ensure PAM Enforces Password Requirements - Minimum Digit Charactersmedium
pass
Ensure PAM Enforces Password Requirements - Minimum Lowercase Charactersmedium
pass
Ensure PAM Enforces Password Requirements - Minimum Different Categoriesmedium
pass
Ensure PAM Enforces Password Requirements - Minimum Lengthmedium
pass
Ensure PAM Enforces Password Requirements - Minimum Special Charactersmedium
pass
Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted Per-Sessionmedium
pass
Ensure PAM Enforces Password Requirements - Minimum Uppercase Charactersmedium
pass
Set Password Hashing Algorithm
Set Password Hashing Algorithm in /etc/login.defsmedium
pass
Protect Accounts by Restricting Password-Based Login
Ensure shadow group is emptymedium
pass
Set Password Expiration Parameters
Set Existing Passwords Maximum Agemedium
pass
Set Existing Passwords Minimum Agemedium
pass
Verify Proper Storage and Existence of Password Hashes
Verify All Account Password Hashes are Shadowedmedium
pass
Ensure all users last password change date is in the pastmedium
pass
All GIDs referenced in /etc/passwd must be defined in /etc/grouplow
pass
Ensure There Are No Accounts With Blank or Null Passwordshigh
pass
Verify No .forward Files Existmedium
pass
Verify No netrc Files Existmedium
pass
Restrict Root Logins
Verify Only Root Has UID 0high
pass
Verify Root Has A Primary GID 0high
pass
Ensure the Group Used by pam_wheel Module Exists on System and is Emptymedium
pass
Enforce Usage of pam_wheel with Group Parameter for su Authenticationmedium
pass
Ensure All Groups on the System Have Unique Group IDmedium
pass
Ensure All Groups on the System Have Unique Group Namesmedium
pass
Secure Session Configuration Files for Login Accounts
Ensure that No Dangerous Directories Exist in Root's Path
Ensure that Root's Path Does Not Include World or Group-Writable Directoriesmedium
pass
Ensure that Root's Path Does Not Include Relative Paths or Null Directoriesunknown
pass
Ensure that Users Have Sensible Umask Values
Ensure the Default Bash Umask is Set Correctlymedium
pass
Ensure the Default Umask is Set Correctly in /etc/profilemedium
pass
Ensure the Default Umask is Set Correctly For Interactive Usersmedium
pass
Set Interactive Session Timeoutmedium
pass
User Initialization Files Must Be Group-Owned By The Primary Groupmedium
pass
User Initialization Files Must Not Run World-Writable Programsmedium
pass
User Initialization Files Must Be Owned By the Primary Usermedium
pass
All Interactive Users Home Directories Must Existmedium
pass
All Interactive User Home Directories Must Be Group-Owned By The Primary Groupmedium
pass
All Interactive User Home Directories Must Be Owned By The Primary Usermedium
pass
All Interactive User Home Directories Must Have mode 0750 Or Less Permissivemedium
pass
System Accounting with auditd
Configure auditd Rules for Comprehensive Auditing
System Audit Logs Must Have Mode 0750 or Less Permissivemedium
notapplicable
System Audit Logs Must Be Group Owned By Rootmedium
notapplicable
Audit Configuration Files Must Be Owned By Group rootmedium
notapplicable
Audit Configuration Files Must Be Owned By Rootmedium
notapplicable
System Audit Logs Must Be Owned By Rootmedium
notapplicable
System Audit Logs Must Have Mode 0640 or Less Permissivemedium
notapplicable
AppArmor
Ensure AppArmor is installedmedium
pass
All AppArmor Profiles are in enforce or complain modemedium
pass
GRUB2 bootloader configuration
Non-UEFI GRUB2 bootloader configuration
Verify /boot/grub/grub.cfg User Ownershipmedium
notapplicable
Verify /boot/grub/grub.cfg Permissionsmedium
notapplicable
Set Boot Loader Password in grub2high
notapplicable
UEFI GRUB2 bootloader configuration
Set the UEFI Boot Loader Passwordhigh
notapplicable
Configure Syslog 2x unknown
systemd-journald 1x unknown
Install systemd-journal-remote Packagemedium
pass
Enable systemd-journald Servicemedium
unknown
Ensure journald is configured to compress large log filesmedium
pass
Ensure journald is configured to write log files to persistent diskmedium
pass
Disable systemd-journal-remote Socketmedium
pass
Configure rsyslogd to Accept Remote Messages If Acting as a Log Server
Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Servermedium
pass
Rsyslog Logs Sent To Remote Host
Ensure Logs Sent To Remote Hostmedium
pass
Ensure rsyslog is Installedmedium
pass
Enable rsyslog Servicemedium
unknown
Ensure rsyslog Default File Permissions Configuredmedium
pass
Network Configuration and Firewalls 1x unknown
iptables and ip6tables
Inspect and Activate Default Rules
Set Default ip6tables Policy for Incoming Packetsmedium
notapplicable
Set configuration for IPv6 loopback trafficmedium
notapplicable
Set configuration for loopback trafficmedium
notapplicable
Strengthen the Default Ruleset
Ensure ip6tables Firewall Rules Exist for All Open Portsmedium
notapplicable
Ensure iptables Firewall Rules Exist for All Open Portsmedium
notapplicable
Set Default iptables Policy for Incoming Packetsmedium
notapplicable
Install iptables Packagemedium
pass
Remove iptables-persistent Packagemedium
pass
IPv6
Configure IPv6 Settings if Necessary
Configure Accepting Router Advertisements on All IPv6 Interfacesmedium
pass
Disable Accepting ICMP Redirects for All IPv6 Interfacesmedium
pass
Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfacesmedium
pass
Disable Kernel Parameter for IPv6 Forwardingmedium
pass
Disable Accepting Router Advertisements on all IPv6 Interfaces by Defaultmedium
pass
Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfacesmedium
pass
Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces by Defaultmedium
pass
Kernel Parameters Which Affect Networking
Network Related Kernel Runtime Parameters for Hosts and Routers
Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfacesmedium
pass
Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfacesunknown
pass
Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfacesmedium
pass
Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfacesmedium
pass
Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfacesmedium
pass
Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces by Defaultmedium
pass
Enable Kernel Paremeter to Log Martian Packets on all IPv4 Interfaces by Defaultunknown
pass
Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces by Defaultmedium
pass
Configure Kernel Parameter for Accepting Secure Redirects By Defaultmedium
pass
Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfacesmedium
pass
Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfacesunknown
pass
Enable Kernel Parameter to Use TCP Syncookies on Network Interfacesmedium
pass
Network Parameters for Hosts Only
Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfacesmedium
pass
Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces by Defaultmedium
pass
Disable Kernel Parameter for IP Forwarding on IPv4 Interfacesmedium
pass
nftables 1x unknown
Install nftables Packagemedium
pass
Verify nftables Service is Enabledmedium
unknown
Ensure nftables rules are permanentmedium
pass
Ensure Base Chains Exist for Nftablesmedium
pass
Set nftables configuration for loopback trafficmedium
pass
Ensure a Table Exists for Nftablesmedium
pass
Uncomplicated Firewall (ufw)
Remove ufw Packagemedium
pass
Verify ufw Enabledmedium
notapplicable
Ensure ufw Default Deny Firewall Policymedium
notapplicable
Set UFW Loopback Trafficmedium
notapplicable
Ensure ufw Firewall Rules Exist for All Open Portsmedium
notapplicable
Wireless Networking
Disable Wireless Through Software Configuration
Deactivate Wireless Network Interfacesmedium
pass
File Permissions and Masks
Verify Permissions on Important Files and Directories
Verify Group Who Owns Backup group Filemedium
pass
Verify Group Who Owns Backup gshadow Filemedium
pass
Verify Group Who Owns Backup passwd Filemedium
pass
Verify User Who Owns Backup shadow Filemedium
pass
Verify Group Who Owns group Filemedium
pass
Verify Group Who Owns gshadow Filemedium
pass
Verify Group Who Owns passwd Filemedium
pass
Verify Group Who Owns shadow Filemedium
pass
Verify User Who Owns Backup group Filemedium
pass
Verify User Who Owns Backup gshadow Filemedium
pass
Verify User Who Owns Backup passwd Filemedium
pass
Verify Group Who Owns Backup shadow Filemedium
pass
Verify User Who Owns group Filemedium
pass
Verify User Who Owns gshadow Filemedium
pass
Verify User Who Owns passwd Filemedium
pass
Verify User Who Owns shadow Filemedium
pass
Verify Permissions on Backup group Filemedium
pass
Verify Permissions on Backup gshadow Filemedium
pass
Verify Permissions on Backup passwd Filemedium
pass
Verify Permissions on Backup shadow Filemedium
pass
Verify Permissions on group Filemedium
pass
Verify Permissions on gshadow Filemedium
pass
Verify Permissions on passwd Filemedium
pass
Verify Permissions on shadow Filemedium
pass
Verify File Permissions Within Some Important Directories
Verify that audit tools are owned by group rootmedium
pass
Verify that audit tools are owned by rootmedium
pass
Verify that audit tools Have Mode 0755 or lessmedium
pass
Verify Permissions on /etc/audit/auditd.confmedium
pass
Verify Permissions on /etc/audit/rules.d/*.rulesmedium
pass
Ensure No World-Writable Files Existmedium
pass
Ensure All Files Are Owned by a Groupmedium
pass
Ensure All Files Are Owned by a Usermedium
pass
Verify permissions of log filesmedium
pass
Restrict Dynamic Mounting and Unmounting of Filesystems
Disable the Automountermedium
pass
Disable Mounting of cramfslow
pass
Disable Modprobe Loading of USB Storage Drivermedium
pass
Restrict Partition Mount Options
Add nodev Option to /dev/shmmedium
pass
Add nosuid Option to /dev/shmmedium
pass
Add nodev Option to /homeunknown
notapplicable
Add nosuid Option to /homemedium
notapplicable
Add nodev Option to /tmpmedium
notapplicable
Add noexec Option to /tmpmedium
notapplicable
Add nosuid Option to /tmpmedium
notapplicable
Add nodev Option to /var/log/auditmedium
notapplicable
Add noexec Option to /var/log/auditmedium
notapplicable
Add nosuid Option to /var/log/auditmedium
notapplicable
Add nodev Option to /var/logmedium
notapplicable
Add noexec Option to /var/logmedium
notapplicable
Add nosuid Option to /var/logmedium
notapplicable
Add nodev Option to /varmedium
notapplicable
Add nosuid Option to /varmedium
notapplicable
Add nodev Option to /var/tmpmedium
notapplicable
Add noexec Option to /var/tmpmedium
notapplicable
Add nosuid Option to /var/tmpmedium
notapplicable
Restrict Programs from Dangerous Execution Patterns
Disable Core Dumps
Disable Core Dumps for All Usersmedium
pass
Enable ExecShield
Enable Randomized Layout of Virtual Address Spacemedium
pass
Services 1x unknown
Apport Service
Disable Apport Serviceunknown
pass
Avahi Server
Disable Avahi Server if Possible
Uninstall avahi Server Packagemedium
pass
Disable Avahi Server Softwaremedium
pass
Cron and At Daemons 1x unknown
Restrict at and cron to Authorized Users if Necessary
Ensure that /etc/at.deny does not existmedium
pass
Ensure that /etc/cron.deny does not existmedium
pass
Verify Group Who Owns /etc/at.allow filemedium
pass
Verify Group Who Owns /etc/cron.allow filemedium
pass
Verify User Who Owns /etc/at.allow filemedium
pass
Verify User Who Owns /etc/cron.allow filemedium
pass
Verify Permissions on /etc/at.allow filemedium
pass
Verify Permissions on /etc/cron.allow filemedium
pass
Enable cron Servicemedium
unknown
Verify Group Who Owns cron.dmedium
pass
Verify Group Who Owns cron.dailymedium
pass
Verify Group Who Owns cron.hourlymedium
pass
Verify Group Who Owns cron.monthlymedium
pass
Verify Group Who Owns cron.weeklymedium
pass
Verify Group Who Owns Crontabmedium
pass
Verify Owner on cron.dmedium
pass
Verify Owner on cron.dailymedium
pass
Verify Owner on cron.hourlymedium
pass
Verify Owner on cron.monthlymedium
pass
Verify Owner on cron.weeklymedium
pass
Verify Owner on crontabmedium
pass
Verify Permissions on cron.dmedium
pass
Verify Permissions on cron.dailymedium
pass
Verify Permissions on cron.hourlymedium
pass
Verify Permissions on cron.monthlymedium
pass
Verify Permissions on cron.weeklymedium
pass
Verify Permissions on crontabmedium
pass
Deprecated services
Uninstall the nis packagelow
pass
DHCP
Disable DHCP Server
Uninstall DHCP Server Packagemedium
pass
DNS Server
Disable DNS Server
Uninstall bind Packagelow
pass
FTP Server
Disable vsftpd if Possible
Uninstall vsftpd Packagehigh
pass
Web Server
Disable Apache if Possible
Uninstall httpd Packageunknown
pass
Disable NGINX if Possible
Uninstall nginx Packageunknown
pass
IMAP and POP3 Server
Disable Cyrus IMAP
Uninstall cyrus-imapd Packageunknown
pass
Disable Dovecot
Uninstall dovecot Packageunknown
pass
LDAP
Configure OpenLDAP Clients
Ensure LDAP client is not installedlow
pass
Configure OpenLDAP Server
Uninstall openldap-servers Packagelow
pass
Mail Server Software
Configure SMTP For Mail Clients
Disable Postfix Network Listeningmedium
pass
Ensure Mail Transfer Agent is not Listening on any non-loopback Addressmedium
pass
NFS and RPC
Disable All NFS Services if Possible
Disable Services Used Only by NFS
Uninstall rpcbind Packagelow
pass
Uninstall nfs-kernel-server Packagelow
pass
Network Time Protocol
Install the systemd_timesyncd Servicehigh
pass
The Chronyd service is enabledmedium
notapplicable
Enable the NTP Daemonhigh
notapplicable
Ensure that chronyd is running under chrony user accountmedium
notapplicable
Configure server restrictions for ntpdmedium
notapplicable
Configure ntpd To Run As ntp Usermedium
notapplicable
Obsolete Services
Rlogin, Rsh, and Rexec
Uninstall rsh Packageunknown
pass
Remove Rsh Trust Fileshigh
pass
Chat/Messaging Services
Uninstall talk Packagemedium
pass
Telnet
Remove telnet Clientslow
pass
Print Support
Uninstall CUPS Packageunknown
pass
Disable the CUPS Serviceunknown
pass
Proxy Server
Disable Squid if Possible
Uninstall squid Packageunknown
pass
Samba(SMB) Microsoft Windows File Sharing Server
Disable Samba if Possible
Uninstall Samba Packageunknown
pass
SNMP Server
Disable SNMP Server if Possible
Uninstall net-snmp Packageunknown
pass
SSH Server
Configure OpenSSH Server if Necessary
Set SSH Client Alive Count Maxmedium
pass
Set SSH Client Alive Intervalmedium
pass
Disable Host-Based Authenticationmedium
pass
Disable SSH Access via Empty Passwordshigh
pass
Disable SSH Support for .rhosts Filesmedium
pass
Do Not Allow SSH Environment Optionsmedium
pass
Enable PAMmedium
pass
Enable SSH Warning Bannermedium
pass
Set LogLevel to INFOlow
pass
Set SSH authentication attempt limitmedium
pass
Set SSH MaxSessions limitmedium
pass
Ensure SSH MaxStartups is configuredmedium
pass
Use Only Strong Ciphersmedium
pass
Use Only Strong Key Exchange algorithmsmedium
pass
Use Only Strong MACsmedium
pass
Verify Group Who Owns SSH Server config filemedium
pass
Verify Owner on SSH Server config filemedium
pass
Verify Permissions on SSH Server config filemedium
pass
Verify Permissions on SSH Server Private *_key Key Filesmedium
pass
Verify Permissions on SSH Server Public *.pub Key Filesmedium
pass
X Window System
Disable X Windows
Remove the X Windows Package Groupmedium
pass

Result Details

Install AIDExccdf_org.ssgproject.content_rule_package_aide_installed medium

Install AIDE

Rule IDxccdf_org.ssgproject.content_rule_package_aide_installed
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R51), 1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9, 5.10.1.3, APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06, CCI-002696, CCI-002699, CCI-001744, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6, 1034, 1288, 1341, 1417, A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3, CM-6(a), DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3, Req-11.5, SRG-OS-000445-GPOS-00199, 1.3.1

Description

The aide package can be installed with the following command:

$ apt-get install aide

Rationale

The AIDE package must be installed if it is to be available for integrity checking.

Build and Test AIDE Databasexccdf_org.ssgproject.content_rule_aide_build_database medium

Build and Test AIDE Database

Rule IDxccdf_org.ssgproject.content_rule_aide_build_database
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R51), 1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9, 5.10.1.3, APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3, CM-6(a), DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3, Req-11.5, SRG-OS-000445-GPOS-00199, 1.3.1

Description

Run the following command to generate a new database:

$ sudo aideinit
By default, the database will be written to the file /var/lib/aide/aide.db.new. Storing the database, the configuration file /etc/aide.conf, and the binary /usr/bin/aide (or hashes of these files), in a secure location (such as on read-only media) provides additional assurance about their integrity. The newly-generated database can be installed as follows:
$ sudo cp /var/lib/aide/aide.db.new /var/lib/aide/aide.db
To initiate a manual check, run the following command:
$ sudo /usr/bin/aide --check
If this check produces any unexpected output, investigate.

Rationale

For AIDE to be effective, an initial database of "known-good" information about files must be captured and it should be able to be verified against the installed files.

Configure AIDE to Verify the Audit Toolsxccdf_org.ssgproject.content_rule_aide_check_audit_tools medium

Configure AIDE to Verify the Audit Tools

Rule IDxccdf_org.ssgproject.content_rule_aide_check_audit_tools
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  CCI-001496, AU-9(3), AU-9(3).1, SRG-OS-000278-GPOS-00108, 4.1.4.11

Description

The operating system file integrity tool must be configured to protect the integrity of the audit tools.

Rationale

Protecting the integrity of the tools used for auditing purposes is a critical step toward ensuring the integrity of audit information. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Audit tools include but are not limited to vendor-provided and open-source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. It is not uncommon for attackers to replace the audit tools or inject code into the existing tools to provide the capability to hide or erase system activity from the audit logs. To address this risk, audit tools must be cryptographically signed to provide the capability to identify when the audit tools have been modified, manipulated, or replaced. An example is a checksum hash of the file or files.

Configure Periodic Execution of AIDExccdf_org.ssgproject.content_rule_aide_periodic_cron_checking medium

Configure Periodic Execution of AIDE

Rule IDxccdf_org.ssgproject.content_rule_aide_periodic_cron_checking
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R51), 1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9, 5.10.1.3, APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06, CCI-001744, CCI-002699, CCI-002702, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4, SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6, A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3, SI-7, SI-7(1), CM-6(a), DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3, Req-11.5, SRG-OS-000363-GPOS-00150, SRG-OS-000446-GPOS-00200, SRG-OS-000447-GPOS-00201, 1.3.2

Description

At a minimum, AIDE should be configured to run a weekly scan. To implement a daily execution of AIDE at 4:05am using cron, add the following line to /etc/crontab:

05 4 * * * root /usr/bin/aide --config /etc/aide/aide.conf --check
To implement a weekly execution of AIDE at 4:05am using cron, add the following line to /etc/crontab:
05 4 * * 0 root /usr/bin/aide --config /etc/aide/aide.conf --check
AIDE can be executed periodically through other means; this is merely one example. The usage of cron's special time codes, such as @daily and @weekly is acceptable.

Rationale

By default, AIDE does not install itself for periodic execution. Periodically running AIDE is necessary to reveal unexpected changes in installed files.

Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security.

Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's Information Management Officer (IMO)/Information System Security Officer (ISSO) and System Administrators (SAs) must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item.

Disable the GNOME3 Login User Listxccdf_org.ssgproject.content_rule_dconf_gnome_disable_user_list medium

Disable the GNOME3 Login User List

Rule IDxccdf_org.ssgproject.content_rule_dconf_gnome_disable_user_list
Result
notapplicable
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  CM-6(a), AC-23, SRG-OS-000480-GPOS-00227, 1.8.3

Description

In the default graphical environment, users logging directly into the system are greeted with a login screen that displays all known users. This functionality should be disabled by setting disable-user-list to true.

To disable, add or edit disable-user-list to /etc/dconf/db/gdm.d/00-security-settings. For example:

[org/gnome/login-screen]
disable-user-list=true
Once the setting has been added, add a lock to /etc/dconf/db/gdm.d/locks/00-security-settings-lock to prevent user modification. For example:
/org/gnome/login-screen/disable-user-list
After the settings have been set, run dconf update.

Rationale

Leaving the user list enabled is a security risk since it allows anyone with physical access to the system to quickly enumerate known user accounts without logging in.

Disable XDMCP in GDMxccdf_org.ssgproject.content_rule_gnome_gdm_disable_xdmcp high

Disable XDMCP in GDM

Rule IDxccdf_org.ssgproject.content_rule_gnome_gdm_disable_xdmcp
Result
notapplicable
Time2024-04-05T12:58:22
Severityhigh
Identifiers and References

References:  1.8.10

Description

XDMCP is an unencrypted protocol, and therefore, presents a security risk, see e.g. XDMCP Gnome docs. To disable XDMCP support in Gnome, set Enable to false under the [xdmcp] configuration section in /etc/gdm/custom.conf. For example:

[xdmcp]
Enable=false

Rationale

XDMCP provides unencrypted remote access through the Gnome Display Manager (GDM) which does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to login using XDMCP, the privileged user password could be compromised due to typed XEvents and keystrokes will traversing over the network in clear text.

Disable GNOME3 Automountingxccdf_org.ssgproject.content_rule_dconf_gnome_disable_automount medium

Disable GNOME3 Automounting

Rule IDxccdf_org.ssgproject.content_rule_dconf_gnome_disable_automount
Result
notapplicable
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  12, 16, APO13.01, DSS01.04, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, 3.1.7, CCI-000366, CCI-000778, CCI-001958, 4.3.3.2.2, 4.3.3.5.2, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.13, SR 1.2, SR 1.4, SR 1.5, SR 1.9, SR 2.1, SR 2.6, A.11.2.6, A.13.1.1, A.13.2.1, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.AC-6, SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227, 1.8.6

Description

The system's default desktop environment, GNOME3, will mount devices and removable media (such as DVDs, CDs and USB flash drives) whenever they are inserted into the system. To disable automount within GNOME3, add or set automount to false in /etc/dconf/db/local.d/00-security-settings. For example:

[org/gnome/desktop/media-handling]
automount=false
Once the settings have been added, add a lock to /etc/dconf/db/local.d/locks/00-security-settings-lock to prevent user modification. For example:
/org/gnome/desktop/media-handling/automount
After the settings have been set, run dconf update.

Rationale

Disabling automatic mounting in GNOME3 can prevent the introduction of malware via removable media. It will, however, also prevent desktop users from legitimate use of removable media.

Disable GNOME3 Automount Openingxccdf_org.ssgproject.content_rule_dconf_gnome_disable_automount_open medium

Disable GNOME3 Automount Opening

Rule IDxccdf_org.ssgproject.content_rule_dconf_gnome_disable_automount_open
Result
notapplicable
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  12, 16, APO13.01, DSS01.04, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, 3.1.7, CCI-000366, CCI-000778, CCI-001958, 4.3.3.2.2, 4.3.3.5.2, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.13, SR 1.2, SR 1.4, SR 1.5, SR 1.9, SR 2.1, SR 2.6, A.11.2.6, A.13.1.1, A.13.2.1, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.AC-6, SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227, 1.8.6

Description

The system's default desktop environment, GNOME3, will mount devices and removable media (such as DVDs, CDs and USB flash drives) whenever they are inserted into the system. To disable automount-open within GNOME3, add or set automount-open to false in /etc/dconf/db/local.d/00-security-settings. For example:

[org/gnome/desktop/media-handling]
automount-open=false
Once the settings have been added, add a lock to /etc/dconf/db/local.d/locks/00-security-settings-lock to prevent user modification. For example:
/org/gnome/desktop/media-handling/automount-open
After the settings have been set, run dconf update.

Rationale

Automatically mounting file systems permits easy introduction of unknown devices, thereby facilitating malicious activity. Disabling automatic mounting in GNOME3 can prevent the introduction of malware via removable media. It will, however, also prevent desktop users from legitimate use of removable media.

Disable GNOME3 Automount runningxccdf_org.ssgproject.content_rule_dconf_gnome_disable_autorun low

Disable GNOME3 Automount running

Rule IDxccdf_org.ssgproject.content_rule_dconf_gnome_disable_autorun
Result
notapplicable
Time2024-04-05T12:58:22
Severitylow
Identifiers and References

References:  12, 16, APO13.01, DSS01.04, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, 3.1.7, CCI-000366, CCI-000778, CCI-001958, 4.3.3.2.2, 4.3.3.5.2, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.13, SR 1.2, SR 1.4, SR 1.5, SR 1.9, SR 2.1, SR 2.6, A.11.2.6, A.13.1.1, A.13.2.1, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.AC-6, SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227, 1.8.8

Description

The system's default desktop environment, GNOME3, will mount devices and removable media (such as DVDs, CDs and USB flash drives) whenever they are inserted into the system. To disable autorun-never within GNOME3, add or set autorun-never to true in /etc/dconf/db/local.d/00-security-settings. For example:

[org/gnome/desktop/media-handling]
autorun-never=true
Once the settings have been added, add a lock to /etc/dconf/db/local.d/locks/00-security-settings-lock to prevent user modification. For example:
/org/gnome/desktop/media-handling/autorun-never
After the settings have been set, run dconf update.

Rationale

Automatically mounting file systems permits easy introduction of unknown devices, thereby facilitating malicious activity. Disabling automatic mount running in GNOME3 can prevent the introduction of malware via removable media. It will, however, also prevent desktop users from legitimate use of removable media.

Set GNOME3 Screensaver Lock Delay After Activation Periodxccdf_org.ssgproject.content_rule_dconf_gnome_screensaver_lock_delay medium

Set GNOME3 Screensaver Lock Delay After Activation Period

Rule IDxccdf_org.ssgproject.content_rule_dconf_gnome_screensaver_lock_delay
Result
notapplicable
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.10, CCI-000056, CCI-000057, CCI-000060, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, AC-11(a), CM-6(a), PR.AC-7, FMT_MOF_EXT.1, Req-8.1.8, SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012, 1.8.5

Description

To activate the locking delay of the screensaver in the GNOME3 desktop when the screensaver is activated, add or set lock-delay to uint32 0 in /etc/dconf/db/local.d/00-security-settings. For example:

[org/gnome/desktop/screensaver]
lock-delay=uint32 0
After the settings have been set, run dconf update.

Rationale

A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to logout because of the temporary nature of the absense.

Enable GNOME3 Screensaver Lock After Idle Periodxccdf_org.ssgproject.content_rule_dconf_gnome_screensaver_lock_enabled medium

Enable GNOME3 Screensaver Lock After Idle Period

Rule IDxccdf_org.ssgproject.content_rule_dconf_gnome_screensaver_lock_enabled
Result
notapplicable
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1, 12, 15, 16, 5.5.5, DSS05.04, DSS05.10, DSS06.10, 3.1.10, CCI-000056, CCI-000058, CCI-000060, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), PR.AC-7, FMT_MOF_EXT.1, Req-8.1.8, SRG-OS-000028-GPOS-00009, SRG-OS-000030-GPOS-00011, 1.8.4

Description

To activate locking of the screensaver in the GNOME3 desktop when it is activated, add or set lock-enabled to true in /etc/dconf/db/local.d/00-security-settings. For example:

[org/gnome/desktop/screensaver]
lock-enabled=true
Once the settings have been added, add a lock to /etc/dconf/db/local.d/locks/00-security-settings-lock to prevent user modification. For example:
/org/gnome/desktop/screensaver/lock-enabled
After the settings have been set, run dconf update.

Rationale

A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to logout because of the temporary nature of the absense.

Install sudo Packagexccdf_org.ssgproject.content_rule_package_sudo_installed medium

Install sudo Package

Rule IDxccdf_org.ssgproject.content_rule_package_sudo_installed
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R19), 1382, 1384, 1386, CM-6(a), FMT_MOF_EXT.1, Req-10.2.1.5, SRG-OS-000324-GPOS-00125, 5.3.1

Description

The sudo package can be installed with the following command:

$ apt-get install sudo

Rationale

sudo is a program designed to allow a system administrator to give limited root privileges to users and log root activity. The basic philosophy is to give as few privileges as possible but still allow system users to get their work done.

Ensure Only Users Logged In To Real tty Can Execute Sudo - sudo use_ptyxccdf_org.ssgproject.content_rule_sudo_add_use_pty medium

Ensure Only Users Logged In To Real tty Can Execute Sudo - sudo use_pty

Rule IDxccdf_org.ssgproject.content_rule_sudo_add_use_pty
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R58), Req-10.2.1.5, 5.3.2

Description

The sudo use_pty tag, when specified, will only execute sudo commands from users logged in to a real tty. This should be enabled by making sure that the use_pty tag exists in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/.

Rationale

Requiring that sudo commands be run in a pseudo-terminal can prevent an attacker from retaining access to the user's terminal after the main program has finished executing.

Ensure Sudo Logfile Exists - sudo logfilexccdf_org.ssgproject.content_rule_sudo_custom_logfile low

Ensure Sudo Logfile Exists - sudo logfile

Rule IDxccdf_org.ssgproject.content_rule_sudo_custom_logfile
Result
pass
Time2024-04-05T12:58:22
Severitylow
Identifiers and References

References:  Req-10.2.1.5, 5.3.3

Description

A custom log sudo file can be configured with the 'logfile' tag. This rule configures a sudo custom logfile at the default location suggested by CIS, which uses /var/log/sudo.log.

Rationale

A sudo log file simplifies auditing of sudo commands.

Ensure Users Re-Authenticate for Privilege Escalation - sudo !authenticatexccdf_org.ssgproject.content_rule_sudo_remove_no_authenticate medium

Ensure Users Re-Authenticate for Privilege Escalation - sudo !authenticate

Rule IDxccdf_org.ssgproject.content_rule_sudo_remove_no_authenticate
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R5), BP28(R59), 1, 12, 15, 16, 5, DSS05.04, DSS05.10, DSS06.03, DSS06.10, CCI-002038, 4.3.3.5.1, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-11, CM-6(a), PR.AC-1, PR.AC-7, SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158, 5.3.5

Description

The sudo !authenticate option, when specified, allows a user to execute commands using sudo without having to authenticate. This should be disabled by making sure that the !authenticate option does not exist in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/.

Rationale

Without re-authentication, users may access resources or perform tasks for which they do not have authorization.

When operating systems provide the capability to escalate a functional capability, it is critical that the user re-authenticate.

Require Re-Authentication When Using the sudo Commandxccdf_org.ssgproject.content_rule_sudo_require_reauthentication medium

Require Re-Authentication When Using the sudo Command

Rule IDxccdf_org.ssgproject.content_rule_sudo_require_reauthentication
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  CCI-002038, IA-11, SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158, 5.3.6

Description

The sudo timestamp_timeout tag sets the amount of time sudo password prompt waits. The default timestamp_timeout value is 5 minutes. The timestamp_timeout should be configured by making sure that the timestamp_timeout tag exists in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/. If the value is set to an integer less than 0, the user's time stamp will not expire and the user will not have to re-authenticate for privileged actions until the user's session is terminated.

Rationale

Without re-authentication, users may access resources or perform tasks for which they do not have authorization.

When operating systems provide the capability to escalate a functional capability, it is critical that the user re-authenticate.

Enable GNOME3 Login Warning Bannerxccdf_org.ssgproject.content_rule_dconf_gnome_banner_enabled medium

Enable GNOME3 Login Warning Banner

Rule IDxccdf_org.ssgproject.content_rule_dconf_gnome_banner_enabled
Result
notapplicable
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.9, CCI-000048, CCI-000050, CCI-001384, CCI-001385, CCI-001386, CCI-001387, CCI-001388, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, AC-8(a), AC-8(b), AC-8(c), PR.AC-7, FMT_MOF_EXT.1, SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088, 1.8.2

Description

In the default graphical environment, displaying a login warning banner in the GNOME Display Manager's login screen can be enabled on the login screen by setting banner-message-enable to true.

To enable, add or edit banner-message-enable to /etc/dconf/db/gdm.d/00-security-settings. For example:

[org/gnome/login-screen]
banner-message-enable=true
Once the setting has been added, add a lock to /etc/dconf/db/gdm.d/locks/00-security-settings-lock to prevent user modification. For example:
/org/gnome/login-screen/banner-message-enable
After the settings have been set, run dconf update. The banner text must also be set.

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.

For U.S. Government systems, system use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist.

Modify the System Login Bannerxccdf_org.ssgproject.content_rule_banner_etc_issue medium

Modify the System Login Banner

Rule IDxccdf_org.ssgproject.content_rule_banner_etc_issue
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.9, CCI-000048, CCI-000050, CCI-001384, CCI-001385, CCI-001386, CCI-001387, CCI-001388, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, AC-8(a), AC-8(c), PR.AC-7, FMT_MOF_EXT.1, SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088, 1.7.2

Description

To configure the system login banner edit /etc/issue. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is either:

You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions:
-The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.
-At any time, the USG may inspect and seize data stored on this IS.
-Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.
-This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy.
-Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.


OR:

I've read & consent to terms in IS user agreem't.

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.

System use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist.

Modify the System Login Banner for Remote Connectionsxccdf_org.ssgproject.content_rule_banner_etc_issue_net medium

Modify the System Login Banner for Remote Connections

Rule IDxccdf_org.ssgproject.content_rule_banner_etc_issue_net
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  CCI-000048, CCI-001384, CCI-001385, CCI-001386, CCI-001387, CCI-001388, SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088, 1.7.3

Description

To configure the system login banner edit /etc/issue.net. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is either:

You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions:
-The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.
-At any time, the USG may inspect and seize data stored on this IS.
-Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.
-This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy.
-Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.


OR:

I've read & consent to terms in IS user agreem't.

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.

System use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist.

Modify the System Message of the Day Bannerxccdf_org.ssgproject.content_rule_banner_etc_motd medium

Modify the System Message of the Day Banner

Rule IDxccdf_org.ssgproject.content_rule_banner_etc_motd
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1.7.1

Description

To configure the system message banner edit /etc/motd. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is either:

You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions:
-The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations.
-At any time, the USG may inspect and seize data stored on this IS.
-Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose.
-This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy.
-Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.


OR:

I've read & consent to terms in IS user agreem't.

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.

System use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist.

Verify Group Ownership of System Login Bannerxccdf_org.ssgproject.content_rule_file_groupowner_etc_issue medium

Verify Group Ownership of System Login Banner

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_etc_issue
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1.7.5

Description

To properly set the group owner of /etc/issue, run the command:

$ sudo chgrp root /etc/issue

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.
Proper group ownership will ensure that only root user can modify the banner.

Verify Group Ownership of System Login Banner for Remote Connectionsxccdf_org.ssgproject.content_rule_file_groupowner_etc_issue_net medium

Verify Group Ownership of System Login Banner for Remote Connections

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_etc_issue_net
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1.7.6

Description

To properly set the group owner of /etc/issue.net, run the command:

$ sudo chgrp root /etc/issue.net

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.
Proper group ownership will ensure that only root user can modify the banner.

Verify Group Ownership of Message of the Day Bannerxccdf_org.ssgproject.content_rule_file_groupowner_etc_motd medium

Verify Group Ownership of Message of the Day Banner

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_etc_motd
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1.7.4

Description

To properly set the group owner of /etc/motd, run the command:

$ sudo chgrp root /etc/motd

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.
Proper group ownership will ensure that only root user can modify the banner.

Verify ownership of System Login Bannerxccdf_org.ssgproject.content_rule_file_owner_etc_issue medium

Verify ownership of System Login Banner

Rule IDxccdf_org.ssgproject.content_rule_file_owner_etc_issue
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1.7.5

Description

To properly set the owner of /etc/issue, run the command:

$ sudo chown root /etc/issue 

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.
Proper ownership will ensure that only root user can modify the banner.

Verify ownership of System Login Banner for Remote Connectionsxccdf_org.ssgproject.content_rule_file_owner_etc_issue_net medium

Verify ownership of System Login Banner for Remote Connections

Rule IDxccdf_org.ssgproject.content_rule_file_owner_etc_issue_net
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1.7.6

Description

To properly set the owner of /etc/issue.net, run the command:

$ sudo chown root /etc/issue.net 

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.
Proper ownership will ensure that only root user can modify the banner.

Verify ownership of Message of the Day Bannerxccdf_org.ssgproject.content_rule_file_owner_etc_motd medium

Verify ownership of Message of the Day Banner

Rule IDxccdf_org.ssgproject.content_rule_file_owner_etc_motd
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1.7.4

Description

To properly set the owner of /etc/motd, run the command:

$ sudo chown root /etc/motd 

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.
Proper ownership will ensure that only root user can modify the banner.

Verify permissions on System Login Bannerxccdf_org.ssgproject.content_rule_file_permissions_etc_issue medium

Verify permissions on System Login Banner

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_etc_issue
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1.7.5

Description

To properly set the permissions of /etc/issue, run the command:

$ sudo chmod 0644 /etc/issue

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.
Proper permissions will ensure that only root user can modify the banner.

Verify permissions on System Login Banner for Remote Connectionsxccdf_org.ssgproject.content_rule_file_permissions_etc_issue_net medium

Verify permissions on System Login Banner for Remote Connections

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_etc_issue_net
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1.7.6

Description

To properly set the permissions of /etc/issue.net, run the command:

$ sudo chmod 0644 /etc/issue.net

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.
Proper permissions will ensure that only root user can modify the banner.

Verify permissions on Message of the Day Bannerxccdf_org.ssgproject.content_rule_file_permissions_etc_motd medium

Verify permissions on Message of the Day Banner

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_etc_motd
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1.7.4

Description

To properly set the permissions of /etc/motd, run the command:

$ sudo chmod 0644 /etc/motd

Rationale

Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance.
Proper permissions will ensure that only root user can modify the banner.

Limit Password Reusexccdf_org.ssgproject.content_rule_accounts_password_pam_unix_remember medium

Limit Password Reuse

Rule IDxccdf_org.ssgproject.content_rule_accounts_password_pam_unix_remember
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.8, CCI-000200, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(f), IA-5(1)(e), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.5, SRG-OS-000077-GPOS-00045, 5.4.3

Description

Do not allow users to reuse recent passwords. This can be accomplished by using the remember option for the pam_unix or pam_pwhistory PAM modules.

Rationale

Preventing re-use of previous passwords helps ensure that a compromised password is not re-used by a user.

Warnings
warning  If the system relies on authselect tool to manage PAM settings, the remediation will also use authselect tool. However, if any manual modification was made in PAM files, the authselect integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report.
warning  Newer versions of authselect contain an authselect feature to easily and properly enable pam_pwhistory.so module. If this feature is not yet available in your system, an authselect custom profile must be used to avoid integrity issues in PAM files.
Lock Accounts After Failed Password Attemptsxccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_deny medium

Lock Accounts After Failed Password Attempts

Rule IDxccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_deny
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, 5.5.3, DSS05.04, DSS05.10, DSS06.10, 3.1.8, CCI-000044, CCI-002236, CCI-002237, CCI-002238, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(a), PR.AC-7, FIA_AFL.1, Req-8.1.6, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, 5.4.2

Description

This rule configures the system to lock out accounts after a number of incorrect login attempts using pam_faillock.so. pam_faillock.so module requires multiple entries in pam files. These entries must be carefully defined to work as expected.

Rationale

By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, also known as brute-forcing, is reduced. Limits are imposed by locking the account.

Warnings
warning  If the system relies on authselect tool to manage PAM settings, the remediation will also use authselect tool. However, if any manual modification was made in PAM files, the authselect integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. If the system supports the /etc/security/faillock.conf file, the pam_faillock parameters should be defined in faillock.conf file.
Set Interval For Counting Failed Password Attemptsxccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_interval medium

Set Interval For Counting Failed Password Attempts

Rule IDxccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_interval
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, CCI-000044, CCI-002236, CCI-002237, CCI-002238, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(a), PR.AC-7, FIA_AFL.1, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, 5.4.2

Description

Utilizing pam_faillock.so, the fail_interval directive configures the system to lock out an account after a number of incorrect login attempts within a specified time period.

Rationale

By limiting the number of failed logon attempts the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account.

Warnings
warning  If the system relies on authselect tool to manage PAM settings, the remediation will also use authselect tool. However, if any manual modification was made in PAM files, the authselect integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. If the system supports the /etc/security/faillock.conf file, the pam_faillock parameters should be defined in faillock.conf file.
Set Lockout Time for Failed Password Attemptsxccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_unlock_time medium

Set Lockout Time for Failed Password Attempts

Rule IDxccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_unlock_time
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, 5.5.3, DSS05.04, DSS05.10, DSS06.10, 3.1.8, CCI-000044, CCI-002236, CCI-002237, CCI-002238, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(b), PR.AC-7, FIA_AFL.1, Req-8.1.7, SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005, 5.4.2

Description

This rule configures the system to lock out accounts during a specified time period after a number of incorrect login attempts using pam_faillock.so. pam_faillock.so module requires multiple entries in pam files. These entries must be carefully defined to work as expected. In order to avoid any errors when manually editing these files, it is recommended to use the appropriate tools, such as authselect or authconfig, depending on the OS version. If unlock_time is set to 0, manual intervention by an administrator is required to unlock a user. This should be done using the faillock tool.

Rationale

By limiting the number of failed logon attempts the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account.

Warnings
warning  If the system supports the new /etc/security/faillock.conf file but the pam_faillock.so parameters are defined directly in /etc/pam.d/system-auth and /etc/pam.d/password-auth, the remediation will migrate the unlock_time parameter to /etc/security/faillock.conf to ensure compatibility with authselect tool. The parameters deny and fail_interval, if used, also have to be migrated by their respective remediation.
warning  If the system relies on authselect tool to manage PAM settings, the remediation will also use authselect tool. However, if any manual modification was made in PAM files, the authselect integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. If the system supports the /etc/security/faillock.conf file, the pam_faillock parameters should be defined in faillock.conf file.
Ensure PAM Enforces Password Requirements - Minimum Digit Charactersxccdf_org.ssgproject.content_rule_accounts_password_pam_dcredit medium

Ensure PAM Enforces Password Requirements - Minimum Digit Characters

Rule IDxccdf_org.ssgproject.content_rule_accounts_password_pam_dcredit
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000194, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, Req-8.2.3, SRG-OS-000071-GPOS-00039, 5.4.1

Description

The pam_pwquality module's dcredit parameter controls requirements for usage of digits in a password. When set to a negative number, any password will be required to contain that many digits. When set to a positive number, pam_pwquality will grant +1 additional length credit for each digit. Modify the dcredit setting in /etc/security/pwquality.conf to require the use of a digit in passwords.

Rationale

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. Requiring digits makes password guessing attacks more difficult by ensuring a larger search space.

Ensure PAM Enforces Password Requirements - Minimum Lowercase Charactersxccdf_org.ssgproject.content_rule_accounts_password_pam_lcredit medium

Ensure PAM Enforces Password Requirements - Minimum Lowercase Characters

Rule IDxccdf_org.ssgproject.content_rule_accounts_password_pam_lcredit
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000193, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, Req-8.2.3, SRG-OS-000070-GPOS-00038, 5.4.1

Description

The pam_pwquality module's lcredit parameter controls requirements for usage of lowercase letters in a password. When set to a negative number, any password will be required to contain that many lowercase characters. When set to a positive number, pam_pwquality will grant +1 additional length credit for each lowercase character. Modify the lcredit setting in /etc/security/pwquality.conf to require the use of a lowercase character in passwords.

Rationale

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.
Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possble combinations that need to be tested before the password is compromised. Requiring a minimum number of lowercase characters makes password guessing attacks more difficult by ensuring a larger search space.

Ensure PAM Enforces Password Requirements - Minimum Different Categoriesxccdf_org.ssgproject.content_rule_accounts_password_pam_minclass medium

Ensure PAM Enforces Password Requirements - Minimum Different Categories

Rule IDxccdf_org.ssgproject.content_rule_accounts_password_pam_minclass
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000195, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, SRG-OS-000072-GPOS-00040, 5.4.1

Description

The pam_pwquality module's minclass parameter controls requirements for usage of different character classes, or types, of character that must exist in a password before it is considered valid. For example, setting this value to three (3) requires that any password must have characters from at least three different categories in order to be approved. The default value is zero (0), meaning there are no required classes. There are four categories available:

* Upper-case characters
* Lower-case characters
* Digits
* Special characters (for example, punctuation)
Modify the minclass setting in /etc/security/pwquality.conf entry to require 4 differing categories of characters when changing passwords.

Rationale

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

Requiring a minimum number of character categories makes password guessing attacks more difficult by ensuring a larger search space.

Ensure PAM Enforces Password Requirements - Minimum Lengthxccdf_org.ssgproject.content_rule_accounts_password_pam_minlen medium

Ensure PAM Enforces Password Requirements - Minimum Length

Rule IDxccdf_org.ssgproject.content_rule_accounts_password_pam_minlen
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, 5, 5.6.2.1.1, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000205, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, Req-8.2.3, SRG-OS-000078-GPOS-00046, 5.4.1

Description

The pam_pwquality module's minlen parameter controls requirements for minimum characters required in a password. Add minlen=14 after pam_pwquality to set minimum password length requirements.

Rationale

The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised.
Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromise the password.

Ensure PAM Enforces Password Requirements - Minimum Special Charactersxccdf_org.ssgproject.content_rule_accounts_password_pam_ocredit medium

Ensure PAM Enforces Password Requirements - Minimum Special Characters

Rule IDxccdf_org.ssgproject.content_rule_accounts_password_pam_ocredit
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-001619, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, SRG-OS-000266-GPOS-00101, 5.4.1

Description

The pam_pwquality module's ocredit= parameter controls requirements for usage of special (or "other") characters in a password. When set to a negative number, any password will be required to contain that many special characters. When set to a positive number, pam_pwquality will grant +1 additional length credit for each special character. Modify the ocredit setting in /etc/security/pwquality.conf to equal -1 to require use of a special character in passwords.

Rationale

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. Requiring a minimum number of special characters makes password guessing attacks more difficult by ensuring a larger search space.

Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted Per-Sessionxccdf_org.ssgproject.content_rule_accounts_password_pam_retry medium

Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted Per-Session

Rule IDxccdf_org.ssgproject.content_rule_accounts_password_pam_retry
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1, 11, 12, 15, 16, 3, 5, 9, 5.5.3, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000192, CCI-000366, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CM-6(a), AC-7(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, PR.IP-1, FMT_MOF_EXT.1, SRG-OS-000069-GPOS-00037, SRG-OS-000480-GPOS-00227, 5.4.1

Description

To configure the number of retry prompts that are permitted per-session: Edit the pam_pwquality.so statement in /etc/pam.d/common-password to show retry=3, or a lower value if site policy is more restrictive. The DoD requirement is a maximum of 3 prompts per session.

Rationale

Setting the password retry prompts that are permitted on a per-session basis to a low value requires some software, such as SSH, to re-connect. This can slow down and draw additional attention to some types of password-guessing attacks. Note that this is different from account lockout, which is provided by the pam_faillock module.

Ensure PAM Enforces Password Requirements - Minimum Uppercase Charactersxccdf_org.ssgproject.content_rule_accounts_password_pam_ucredit medium

Ensure PAM Enforces Password Requirements - Minimum Uppercase Characters

Rule IDxccdf_org.ssgproject.content_rule_accounts_password_pam_ucredit
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R18), 1, 12, 15, 16, 5, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000192, CCI-000193, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4), PR.AC-1, PR.AC-6, PR.AC-7, FMT_SMF_EXT.1, Req-8.2.3, SRG-OS-000069-GPOS-00037, SRG-OS-000070-GPOS-00038, 5.4.1

Description

The pam_pwquality module's ucredit= parameter controls requirements for usage of uppercase letters in a password. When set to a negative number, any password will be required to contain that many uppercase characters. When set to a positive number, pam_pwquality will grant +1 additional length credit for each uppercase character. Modify the ucredit setting in /etc/security/pwquality.conf to require the use of an uppercase character in passwords.

Rationale

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

Set Password Hashing Algorithm in /etc/login.defsxccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_logindefs medium

Set Password Hashing Algorithm in /etc/login.defs

Rule IDxccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_logindefs
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R32), 1, 12, 15, 16, 5, 5.6.2.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.13.11, CCI-000196, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 0418, 1055, 1402, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(c), IA-5(1)(c), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, SRG-OS-000073-GPOS-00041, 5.4.4

Description

In /etc/login.defs, add or correct the following line to ensure the system will use yescrypt as the hashing algorithm:

ENCRYPT_METHOD yescrypt

Rationale

Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text.

Using a stronger hashing algorithm makes password cracking attacks more difficult.

Ensure shadow group is emptyxccdf_org.ssgproject.content_rule_ensure_shadow_group_empty medium

Ensure shadow group is empty

Rule IDxccdf_org.ssgproject.content_rule_ensure_shadow_group_empty
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  Req-8.2.1, 6.2.4

Description

The shadow group allows system programs which require access the ability to read the /etc/shadow file. No users should be assigned to the shadow group.

Rationale

Any users assigned to the shadow group would be granted read access to the /etc/shadow file. If attackers can gain read access to the /etc/shadow file, they can easily run a password cracking program against the hashed passwords to break them. Other security information that is stored in the /etc/shadow file (such as expiration) could also be useful to subvert additional user accounts.

Set Existing Passwords Maximum Agexccdf_org.ssgproject.content_rule_accounts_password_set_max_life_existing medium

Set Existing Passwords Maximum Age

Rule IDxccdf_org.ssgproject.content_rule_accounts_password_set_max_life_existing
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  CCI-000199, IA-5(f), IA-5(1)(d), CM-6(a), SRG-OS-000076-GPOS-00044, 5.5.1.2

Description

Configure non-compliant accounts to enforce a 365-day maximum password lifetime restriction by running the following command:

$ sudo chage -M 365 USER

Rationale

Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised.

Set Existing Passwords Minimum Agexccdf_org.ssgproject.content_rule_accounts_password_set_min_life_existing medium

Set Existing Passwords Minimum Age

Rule IDxccdf_org.ssgproject.content_rule_accounts_password_set_min_life_existing
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  CCI-000198, IA-5(f), IA-5(1)(d), CM-6(a), SRG-OS-000075-GPOS-00043, 5.5.1.1

Description

Configure non-compliant accounts to enforce a 24 hours/1 day minimum password lifetime by running the following command:

$ sudo chage -m 1 USER

Rationale

Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse.

Verify All Account Password Hashes are Shadowedxccdf_org.ssgproject.content_rule_accounts_password_all_shadowed medium

Verify All Account Password Hashes are Shadowed

Rule IDxccdf_org.ssgproject.content_rule_accounts_password_all_shadowed
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1, 12, 15, 16, 5, 5.5.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.5.10, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, 1410, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, IA-5(h), CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.2.1, 6.2.1

Description

If any password hashes are stored in /etc/passwd (in the second field, instead of an x or *), the cause of this misconfiguration should be investigated. The account should have its password reset and the hash should be properly stored, or the account should be deleted entirely.

Rationale

The hashes for all user account passwords should be stored in the file /etc/shadow and never in /etc/passwd, which is readable by all users.

Ensure all users last password change date is in the pastxccdf_org.ssgproject.content_rule_accounts_password_last_change_is_in_past medium

Ensure all users last password change date is in the past

Rule IDxccdf_org.ssgproject.content_rule_accounts_password_last_change_is_in_past
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  5.5.1.5

Description

All users should have a password change date in the past.

Rationale

If a user recorded password change date is in the future then they could bypass any set password expiration.

Warnings
warning  Automatic remediation is not available, in order to avoid any system disruption.
All GIDs referenced in /etc/passwd must be defined in /etc/groupxccdf_org.ssgproject.content_rule_gid_passwd_group_same low

All GIDs referenced in /etc/passwd must be defined in /etc/group

Rule IDxccdf_org.ssgproject.content_rule_gid_passwd_group_same
Result
pass
Time2024-04-05T12:58:22
Severitylow
Identifiers and References

References:  1, 12, 15, 16, 5, 5.5.2, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, CCI-000764, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, IA-2, CM-6(a), PR.AC-1, PR.AC-6, PR.AC-7, Req-8.5.a, SRG-OS-000104-GPOS-00051, 6.2.3

Description

Add a group to the system for each GID referenced without a corresponding group.

Rationale

If a user is assigned the Group Identifier (GID) of a group not existing on the system, and a group with the Group Identifier (GID) is subsequently created, the user may have unintended rights to any files associated with the group.

Ensure There Are No Accounts With Blank or Null Passwordsxccdf_org.ssgproject.content_rule_no_empty_passwords_etc_shadow high

Ensure There Are No Accounts With Blank or Null Passwords

Rule IDxccdf_org.ssgproject.content_rule_no_empty_passwords_etc_shadow
Result
pass
Time2024-04-05T12:58:22
Severityhigh
Identifiers and References

References:  CCI-000366, CM-6(b), CM-6.1(iv), SRG-OS-000480-GPOS-00227, 6.2.2

Description

Check the "/etc/shadow" file for blank passwords with the following command:

$ sudo awk -F: '!$2 {print $1}' /etc/shadow
If the command returns any results, this is a finding. Configure all accounts on the system to have a password or lock the account with the following commands: Perform a password reset:
$ sudo passwd [username]
Lock an account:
$ sudo passwd -l [username]

Rationale

If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.

Warnings
warning  Note that this rule is not applicable for systems running within a container. Having user with empty password within a container is not considered a risk, because it should not be possible to directly login into a container anyway.
Verify No .forward Files Existxccdf_org.ssgproject.content_rule_no_forward_files medium

Verify No .forward Files Exist

Rule IDxccdf_org.ssgproject.content_rule_no_forward_files
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  6.2.15

Description

The .forward file specifies an email address to forward the user's mail to.

Rationale

Use of the .forward file poses a security risk in that sensitive data may be inadvertently transferred outside the organization. The .forward file also poses a risk as it can be used to execute commands that may perform unintended actions.

Verify No netrc Files Existxccdf_org.ssgproject.content_rule_no_netrc_files medium

Verify No netrc Files Exist

Rule IDxccdf_org.ssgproject.content_rule_no_netrc_files
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  1, 11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, CCI-000196, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-003-8 R1.3, CIP-003-8 R3, CIP-003-8 R3.1, CIP-003-8 R3.2, CIP-003-8 R3.3, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, IA-5(h), IA-5(1)(c), CM-6(a), IA-5(7), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.PT-3, 6.2.14

Description

The .netrc files contain login information used to auto-login into FTP servers and reside in the user's home directory. These files may contain unencrypted passwords to remote FTP servers making them susceptible to access by unauthorized users and should not be used. Any .netrc files should be removed.

Rationale

Unencrypted passwords for remote FTP servers may be stored in .netrc files.

Verify Only Root Has UID 0xccdf_org.ssgproject.content_rule_accounts_no_uid_except_zero high

Verify Only Root Has UID 0

Rule IDxccdf_org.ssgproject.content_rule_accounts_no_uid_except_zero
Result
pass
Time2024-04-05T12:58:22
Severityhigh
Identifiers and References

References:  1, 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10, 3.1.1, 3.1.5, CCI-000366, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, IA-2, AC-6(5), IA-4(b), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, Req-8.2.1, SRG-OS-000480-GPOS-00227, 6.2.10

Description

If any account other than root has a UID of 0, this misconfiguration should be investigated and the accounts other than root should be removed or have their UID changed.
If the account is associated with system commands or applications the UID should be changed to one greater than "0" but less than "1000." Otherwise assign a UID greater than "1000" that has not already been assigned.

Rationale

An account has root authority if it has a UID of 0. Multiple accounts with a UID of 0 afford more opportunity for potential intruders to guess a password for a privileged account. Proper configuration of sudo is recommended to afford multiple system administrators access to root privileges in an accountable manner.

Verify Root Has A Primary GID 0xccdf_org.ssgproject.content_rule_accounts_root_gid_zero high

Verify Root Has A Primary GID 0

Rule IDxccdf_org.ssgproject.content_rule_accounts_root_gid_zero
Result
pass
Time2024-04-05T12:58:22
Severityhigh
Identifiers and References

References:  Req-8.2.1, 5.5.3

Description

The root user should have a primary group of 0.

Rationale

To help ensure that root-owned files are not inadvertently exposed to other users.

Ensure the Group Used by pam_wheel Module Exists on System and is Emptyxccdf_org.ssgproject.content_rule_ensure_pam_wheel_group_empty medium

Ensure the Group Used by pam_wheel Module Exists on System and is Empty

Rule IDxccdf_org.ssgproject.content_rule_ensure_pam_wheel_group_empty
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  5.3.7

Description

Ensure that the group sugroup referenced by the pam_wheel group parameter exists and has no members. This ensures that no user can run commands with altered privileges through the su command.

Rationale

The su program allows to run commands with a substitute user and group ID. It is commonly used to run commands as the root user. Limiting access to such command is considered a good security practice.

Enforce Usage of pam_wheel with Group Parameter for su Authenticationxccdf_org.ssgproject.content_rule_use_pam_wheel_group_for_su medium

Enforce Usage of pam_wheel with Group Parameter for su Authentication

Rule IDxccdf_org.ssgproject.content_rule_use_pam_wheel_group_for_su
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  5.3.7

Description

To ensure that only users who are members of the group set in the group pam_wheel parameter can run commands with altered privileges through the su command, make sure that the following line exists in the file /etc/pam.d/su:

auth required pam_wheel.so use_uid group=sugroup

Rationale

The su program allows to run commands with a substitute user and group ID. It is commonly used to run commands as the root user. Limiting access to such command is considered a good security practice.

Ensure All Groups on the System Have Unique Group IDxccdf_org.ssgproject.content_rule_group_unique_id medium

Ensure All Groups on the System Have Unique Group ID

Rule IDxccdf_org.ssgproject.content_rule_group_unique_id
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  CCI-000764, SRG-OS-000104-GPOS-00051, 6.2.6

Description

Change the group name or delete groups, so each has a unique id.

Rationale

To assure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system.

Warnings
warning  Automatic remediation of this control is not available due to the unique requirements of each system.
Ensure All Groups on the System Have Unique Group Namesxccdf_org.ssgproject.content_rule_group_unique_name medium

Ensure All Groups on the System Have Unique Group Names

Rule IDxccdf_org.ssgproject.content_rule_group_unique_name
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  6.2.8

Description

Change the group name or delete groups, so each has a unique name.

Rationale

To assure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system.

Warnings
warning  Automatic remediation of this control is not available due to the unique requirements of each system.
Ensure that Root's Path Does Not Include World or Group-Writable Directoriesxccdf_org.ssgproject.content_rule_accounts_root_path_dirs_no_write medium

Ensure that Root's Path Does Not Include World or Group-Writable Directories

Rule IDxccdf_org.ssgproject.content_rule_accounts_root_path_dirs_no_write
Result
pass
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, CCI-000366, 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CM-6(a), CM-6(a), PR.IP-1, 6.2.9

Description

For each element in root's path, run:

# ls -ld DIR
and ensure that write permissions are disabled for group and other.

Rationale

Such entries increase the risk that root could execute code provided by unprivileged users, and potentially malicious code.

Ensure that Root's Path Does Not Include Relative Paths or Null Directoriesxccdf_org.ssgproject.content_rule_root_path_no_dot unknown

Ensure that Root's Path Does Not Include Relative Paths or Null Directories

Rule IDxccdf_org.ssgproject.content_rule_root_path_no_dot
Result
pass
Time2024-04-05T12:58:27
Severityunknown
Identifiers and References

References:  11, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, CCI-000366, 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, CM-6(a), CM-6(a), PR.IP-1, 6.2.9

Description

Ensure that none of the directories in root's path is equal to a single . character, or that it contains any instances that lead to relative path traversal, such as .. or beginning a path without the slash (/) character. Also ensure that there are no "empty" elements in the path, such as in these examples:

PATH=:/bin
PATH=/bin:
PATH=/bin::/sbin
These empty elements have the same effect as a single . character.

Rationale

Including these entries increases the risk that root could execute code from an untrusted location.

Ensure the Default Bash Umask is Set Correctlyxccdf_org.ssgproject.content_rule_accounts_umask_etc_bashrc medium

Ensure the Default Bash Umask is Set Correctly

Rule IDxccdf_org.ssgproject.content_rule_accounts_umask_etc_bashrc
Result
pass
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  BP28(R35), 18, APO13.01, BAI03.01, BAI03.02, BAI03.03, CCI-000366, 4.3.4.3.3, A.14.1.1, A.14.2.1, A.14.2.5, A.6.1.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-6(1), CM-6(a), PR.IP-2, Req-8.6.1, SRG-OS-000480-GPOS-00228, SRG-OS-000480-GPOS-00227, 5.5.4

Description

To ensure the default umask for users of the Bash shell is set properly, add or correct the umask setting in /etc/bashrc to read as follows:

umask 027

Rationale

The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.

Ensure the Default Umask is Set Correctly in /etc/profilexccdf_org.ssgproject.content_rule_accounts_umask_etc_profile medium

Ensure the Default Umask is Set Correctly in /etc/profile

Rule IDxccdf_org.ssgproject.content_rule_accounts_umask_etc_profile
Result
pass
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  BP28(R35), 18, APO13.01, BAI03.01, BAI03.02, BAI03.03, CCI-000366, 4.3.4.3.3, A.14.1.1, A.14.2.1, A.14.2.5, A.6.1.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-6(1), CM-6(a), PR.IP-2, Req-8.6.1, SRG-OS-000480-GPOS-00228, SRG-OS-000480-GPOS-00227, 5.5.4

Description

To ensure the default umask controlled by /etc/profile is set properly, add or correct the umask setting in /etc/profile to read as follows:

umask 027
Note that /etc/profile also reads scrips within /etc/profile.d directory. These scripts are also valid files to set umask value. Therefore, they should also be considered during the check and properly remediated, if necessary.

Rationale

The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.

Ensure the Default Umask is Set Correctly For Interactive Usersxccdf_org.ssgproject.content_rule_accounts_umask_interactive_users medium

Ensure the Default Umask is Set Correctly For Interactive Users

Rule IDxccdf_org.ssgproject.content_rule_accounts_umask_interactive_users
Result
pass
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  CCI-000366, CCI-001814, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00228, 5.5.4

Description

Remove the UMASK environment variable from all interactive users initialization files.

Rationale

The umask controls the default access mode assigned to newly created files. A umask of 077 limits new files to mode 700 or less permissive. Although umask can be represented as a four-digit number, the first digit representing special access modes is typically ignored or required to be 0. This requirement applies to the globally configured system defaults and the local interactive user defaults for each account on the system.

Set Interactive Session Timeoutxccdf_org.ssgproject.content_rule_accounts_tmout medium

Set Interactive Session Timeout

Rule IDxccdf_org.ssgproject.content_rule_accounts_tmout
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  BP28(R29), 1, 12, 15, 16, DSS05.04, DSS05.10, DSS06.10, 3.1.11, CCI-000057, CCI-001133, CCI-002361, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-12, SC-10, AC-2(5), CM-6(a), PR.AC-7, FMT_MOF_EXT.1, Req-8.6.1, SRG-OS-000163-GPOS-00072, SRG-OS-000029-GPOS-00010, 5.5.5

Description

Setting the TMOUT option in /etc/profile ensures that all user sessions will terminate based on inactivity. The value of TMOUT should be exported and read only. The TMOUT setting in a file loaded by /etc/profile, e.g. /etc/profile.d/tmout.sh should read as follows:

TMOUT=900
readonly TMOUT export TMOUT

Rationale

Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended.

User Initialization Files Must Be Group-Owned By The Primary Groupxccdf_org.ssgproject.content_rule_accounts_user_dot_group_ownership medium

User Initialization Files Must Be Group-Owned By The Primary Group

Rule IDxccdf_org.ssgproject.content_rule_accounts_user_dot_group_ownership
Result
pass
Time2024-04-05T12:58:22
Severitymedium
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227, 6.2.17

Description

Change the group owner of interactive users files to the group found in

/etc/passwd
for the user. To change the group owner of a local interactive user home directory, use the following command:
$ sudo chgrp USER_GROUP /home/USER/.INIT_FILE
This rule ensures every initialization file related to an interactive user is group-owned by an interactive user.

Rationale

Local initialization files for interactive users are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon.

Warnings
warning  Due to OVAL limitation, this rule can report a false negative in a specific situation where two interactive users swap the group-ownership of their respective initialization files.
User Initialization Files Must Not Run World-Writable Programsxccdf_org.ssgproject.content_rule_accounts_user_dot_no_world_writable_programs medium

User Initialization Files Must Not Run World-Writable Programs

Rule IDxccdf_org.ssgproject.content_rule_accounts_user_dot_no_world_writable_programs
Result
pass
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227, 6.2.17

Description

Set the mode on files being executed by the user initialization files with the following command:

$ sudo chmod o-w FILE

Rationale

If user start-up files execute world-writable programs, especially in unprotected directories, they could be maliciously modified to destroy user files or otherwise compromise the system at the user level. If the system is compromised at the user level, it is easier to elevate privileges to eventually compromise the system at the root and network level.

User Initialization Files Must Be Owned By the Primary Userxccdf_org.ssgproject.content_rule_accounts_user_dot_user_ownership medium

User Initialization Files Must Be Owned By the Primary User

Rule IDxccdf_org.ssgproject.content_rule_accounts_user_dot_user_ownership
Result
pass
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227, 6.2.17

Description

Set the owner of the user initialization files for interactive users to the primary owner with the following command:

$ sudo chown USER /home/USER/.*
This rule ensures every initialization file related to an interactive user is owned by an interactive user.

Rationale

Local initialization files are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon.

Warnings
warning  Due to OVAL limitation, this rule can report a false negative in a specific situation where two interactive users swap the ownership of their respective initialization files.
All Interactive Users Home Directories Must Existxccdf_org.ssgproject.content_rule_accounts_user_interactive_home_directory_exists medium

All Interactive Users Home Directories Must Exist

Rule IDxccdf_org.ssgproject.content_rule_accounts_user_interactive_home_directory_exists
Result
pass
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227, 6.2.11

Description

Create home directories to all local interactive users that currently do not have a home directory assigned. Use the following commands to create the user home directory assigned in /etc/passwd:

$ sudo mkdir /home/USER

Rationale

If a local interactive user has a home directory defined that does not exist, the user may be given access to the / directory as the current working directory upon logon. This could create a Denial of Service because the user would not be able to access their logon configuration files, and it may give them visibility to system files they normally would not be able to access.

All Interactive User Home Directories Must Be Group-Owned By The Primary Groupxccdf_org.ssgproject.content_rule_file_groupownership_home_directories medium

All Interactive User Home Directories Must Be Group-Owned By The Primary Group

Rule IDxccdf_org.ssgproject.content_rule_file_groupownership_home_directories
Result
pass
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227, 6.2.12

Description

Change the group owner of interactive users home directory to the group found in /etc/passwd. To change the group owner of interactive users home directory, use the following command:

$ sudo chgrp USER_GROUP /home/USER
This rule ensures every home directory related to an interactive user is group-owned by an interactive user. It also ensures that interactive users are group-owners of one and only one home directory.

Rationale

If the Group Identifier (GID) of a local interactive users home directory is not the same as the primary GID of the user, this would allow unauthorized access to the users files, and users that share the same group may not be able to access files that they legitimately should.

Warnings
warning  Due to OVAL limitation, this rule can report a false negative in a specific situation where two interactive users swap the group-ownership of their respective home directories.
All Interactive User Home Directories Must Be Owned By The Primary Userxccdf_org.ssgproject.content_rule_file_ownership_home_directories medium

All Interactive User Home Directories Must Be Owned By The Primary User

Rule IDxccdf_org.ssgproject.content_rule_file_ownership_home_directories
Result
pass
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227, 6.2.12

Description

Change the owner of interactive users home directories to that correct owner. To change the owner of a interactive users home directory, use the following command:

$ sudo chown USER /home/USER
This rule ensures every home directory related to an interactive user is owned by an interactive user. It also ensures that interactive users are owners of one and only one home directory.

Rationale

If a local interactive user does not own their home directory, unauthorized users could access or modify the user's files, and the users may not be able to access their own files.

Warnings
warning  Due to OVAL limitation, this rule can report a false negative in a specific situation where two interactive users swap the ownership of their respective home directories.
All Interactive User Home Directories Must Have mode 0750 Or Less Permissivexccdf_org.ssgproject.content_rule_file_permissions_home_directories medium

All Interactive User Home Directories Must Have mode 0750 Or Less Permissive

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_home_directories
Result
pass
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  CCI-000366, SRG-OS-000480-GPOS-00227, 6.2.13

Description

Change the mode of interactive users home directories to 0750. To change the mode of interactive users home directory, use the following command:

$ sudo chmod 0750 /home/USER

Rationale

Excessive permissions on local interactive user home directories may allow unauthorized access to user files by other users.

System Audit Logs Must Have Mode 0750 or Less Permissivexccdf_org.ssgproject.content_rule_directory_permissions_var_log_audit medium

System Audit Logs Must Have Mode 0750 or Less Permissive

Rule IDxccdf_org.ssgproject.content_rule_directory_permissions_var_log_audit
Result
notapplicable
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8, APO01.06, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA02.01, CCI-000162, CCI-000163, CCI-000164, 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-004-6 R3.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CIP-007-3 R6.5, CM-6(a), AC-6(1), AU-9, DE.AE-3, DE.AE-5, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4, SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, 4.1.4.4

Description

If log_group in /etc/audit/auditd.conf is set to a group other than the root group account, change the mode of the audit log files with the following command:

$ sudo chmod 0750 /var/log/audit

Otherwise, change the mode of the audit log files with the following command:
$ sudo chmod 0700 /var/log/audit

Rationale

If users can write to audit logs, audit trails can be modified or destroyed.

System Audit Logs Must Be Group Owned By Rootxccdf_org.ssgproject.content_rule_file_group_ownership_var_log_audit medium

System Audit Logs Must Be Group Owned By Root

Rule IDxccdf_org.ssgproject.content_rule_file_group_ownership_var_log_audit
Result
notapplicable
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO01.06, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA02.01, 3.3.1, CCI-000162, CCI-000163, CCI-000164, CCI-001314, 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), AU-9(4), DE.AE-3, DE.AE-5, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.5.1, SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084, 4.1.4.3

Description

All audit logs must be group owned by root user. The path for audit log can be configured via log_file parameter in

/etc/audit/auditd.conf
or, by default, the path for audit log is
/var/log/audit/
. To properly set the group owner of /var/log/audit/*, run the command:
$ sudo chgrp root /var/log/audit/*
If log_group in /etc/audit/auditd.conf is set to a group other than the root group account, change the group ownership of the audit logs to this specific group.

Rationale

Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality.

Audit Configuration Files Must Be Owned By Group rootxccdf_org.ssgproject.content_rule_file_groupownership_audit_configuration medium

Audit Configuration Files Must Be Owned By Group root

Rule IDxccdf_org.ssgproject.content_rule_file_groupownership_audit_configuration
Result
notapplicable
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  CCI-000171, SRG-OS-000063-GPOS-00032, 4.1.4.7

Description

All audit configuration files must be owned by group root.

chown :root /etc/audit/audit*.{rules,conf} /etc/audit/rules.d/*

Rationale

Without the capability to restrict which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.

Audit Configuration Files Must Be Owned By Rootxccdf_org.ssgproject.content_rule_file_ownership_audit_configuration medium

Audit Configuration Files Must Be Owned By Root

Rule IDxccdf_org.ssgproject.content_rule_file_ownership_audit_configuration
Result
notapplicable
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  CCI-000171, SRG-OS-000063-GPOS-00032, 4.1.4.6

Description

All audit configuration files must be owned by root user. To properly set the owner of /etc/audit/, run the command:

$ sudo chown root /etc/audit/ 
To properly set the owner of /etc/audit/rules.d/, run the command:
$ sudo chown root /etc/audit/rules.d/ 

Rationale

Without the capability to restrict which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.

System Audit Logs Must Be Owned By Rootxccdf_org.ssgproject.content_rule_file_ownership_var_log_audit_stig medium

System Audit Logs Must Be Owned By Root

Rule IDxccdf_org.ssgproject.content_rule_file_ownership_var_log_audit_stig
Result
notapplicable
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO01.06, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA02.01, 3.3.1, CCI-000162, CCI-000163, CCI-000164, CCI-001314, 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), AU-9(4), DE.AE-3, DE.AE-5, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.5.1, SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084, 4.1.4.2

Description

All audit logs must be owned by root user. The path for audit log can be configured via log_file parameter in

/etc/audit/auditd.conf
or by default, the path for audit log is
/var/log/audit/
. To properly set the owner of /var/log/audit/*, run the command:
$ sudo chown root /var/log/audit/* 

Rationale

Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality.

System Audit Logs Must Have Mode 0640 or Less Permissivexccdf_org.ssgproject.content_rule_file_permissions_var_log_audit medium

System Audit Logs Must Have Mode 0640 or Less Permissive

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_var_log_audit
Result
notapplicable
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8, 5.4.1.1, APO01.06, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA02.01, 3.3.1, CCI-000162, CCI-000163, CCI-000164, CCI-001314, 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), AU-9(4), DE.AE-3, DE.AE-5, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4, Req-10.5, SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084, 4.1.4.1

Description

If log_group in /etc/audit/auditd.conf is set to a group other than the root group account, change the mode of the audit log files with the following command:

$ sudo chmod 0640 audit_file

Otherwise, change the mode of the audit log files with the following command:
$ sudo chmod 0600 audit_file

Rationale

If users can write to audit logs, audit trails can be modified or destroyed.

Ensure AppArmor is installedxccdf_org.ssgproject.content_rule_package_apparmor_installed medium

Ensure AppArmor is installed

Rule IDxccdf_org.ssgproject.content_rule_package_apparmor_installed
Result
pass
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  CCI-001764, CCI-001774, CCI-002165, CCI-002235, SRG-OS-000368-GPOS-00154, SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000312-GPOS-00124, SRG-OS-000324-GPOS-00125, SRG-OS-000370-GPOS-00155, 1.6.1.1

Description

AppArmor provide Mandatory Access Controls.

Rationale

Without a Mandatory Access Control system installed only the default Discretionary Access Control system will be available.

All AppArmor Profiles are in enforce or complain modexccdf_org.ssgproject.content_rule_all_apparmor_profiles_in_enforce_complain_mode medium

All AppArmor Profiles are in enforce or complain mode

Rule IDxccdf_org.ssgproject.content_rule_all_apparmor_profiles_in_enforce_complain_mode
Result
pass
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  1.6.1.3

Description

AppArmor profiles define what resources applications are able to access. To set all profiles to either enforce or complain mode run the following command to set all profiles to enforce mode:

$ sudo aa-enforce /etc/apparmor.d/*
run the following command to set all profiles to complain mode:
$ sudo aa-complain /etc/apparmor.d/*
To list unconfined processes run the following command:
$ sudo apparmor_status | grep processes
Any unconfined processes may need to have a profile created or activated for them and then be restarted.

Rationale

Security configuration requirements vary from site to site. Some sites may mandate a policy that is stricter than the default policy, which is perfectly acceptable. This recommendation is intended to ensure that any policies that exist on the system are activated.

Verify /boot/grub/grub.cfg User Ownershipxccdf_org.ssgproject.content_rule_file_owner_grub2_cfg medium

Verify /boot/grub/grub.cfg User Ownership

Rule IDxccdf_org.ssgproject.content_rule_file_owner_grub2_cfg
Result
notapplicable
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-7.1, 1.4.2

Description

The file /boot/grub/grub.cfg should be owned by the root user to prevent destruction or modification of the file. To properly set the owner of /boot/grub/grub.cfg, run the command:

$ sudo chown root /boot/grub/grub.cfg 

Rationale

Only root should be able to modify important boot parameters.

Verify /boot/grub/grub.cfg Permissionsxccdf_org.ssgproject.content_rule_file_permissions_grub2_cfg medium

Verify /boot/grub/grub.cfg Permissions

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_grub2_cfg
Result
notapplicable
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.4.5, CCI-000225, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 1.4.2

Description

File permissions for /boot/grub/grub.cfg should be set to 600. To properly set the permissions of /boot/grub/grub.cfg, run the command:

$ sudo chmod 600 /boot/grub/grub.cfg

Rationale

Proper permissions ensure that only the root user can modify important boot parameters.

Set Boot Loader Password in grub2xccdf_org.ssgproject.content_rule_grub2_password high

Set Boot Loader Password in grub2

Rule IDxccdf_org.ssgproject.content_rule_grub2_password
Result
notapplicable
Time2024-04-05T12:58:27
Severityhigh
Identifiers and References

References:  BP28(R17), 1, 11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.06, DSS06.10, 3.4.5, CCI-000213, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CM-6(a), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.PT-3, FIA_UAU.1, SRG-OS-000080-GPOS-00048, 1.4.1

Description

The grub2 boot loader should have a superuser account and password protection enabled to protect boot-time settings.

Since plaintext passwords are a security risk, generate a hash for the password by running the following command:

# grub2-mkpasswd-pbkdf2
When prompted, enter the password that was selected.

Using the hash from the output, modify the /etc/grub.d/40_custom file with the following content:
set superusers="boot"
password_pbkdf2 boot grub.pbkdf2.sha512.VeryLongString
NOTE: the bootloader superuser account and password MUST differ from the root account and password. Once the superuser password has been added, update the grub.cfg file by running:
update-grub 

Rationale

Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.

Warnings
warning  To prevent hard-coded passwords, automatic remediation of this control is not available. Remediation must be automated as a component of machine provisioning, or followed manually as outlined above. Also, do NOT manually add the superuser account and password to the grub.cfg file as the grub2-mkconfig command overwrites this file.
Set the UEFI Boot Loader Passwordxccdf_org.ssgproject.content_rule_grub2_uefi_password high

Set the UEFI Boot Loader Password

Rule IDxccdf_org.ssgproject.content_rule_grub2_uefi_password
Result
notapplicable
Time2024-04-05T12:58:27
Severityhigh
Identifiers and References

References:  BP28(R17), 11, 12, 14, 15, 16, 18, 3, 5, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.4.5, CCI-000213, 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), PR.AC-4, PR.AC-6, PR.PT-3, FIA_UAU.1, SRG-OS-000080-GPOS-00048, 1.4.1

Description

The grub2 boot loader should have a superuser account and password protection enabled to protect boot-time settings.

Since plaintext passwords are a security risk, generate a hash for the password by running the following command:

# grub2-mkpasswd-pbkdf2
When prompted, enter the password that was selected.

Using the hash from the output, modify the /etc/grub.d/40_custom file with the following content:
set superusers="boot"
password_pbkdf2 boot grub.pbkdf2.sha512.VeryLongString
NOTE: the bootloader superuser account and password MUST differ from the root account and password. Once the superuser password has been added, update the grub.cfg file by running:
update-grub 

Rationale

Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode.

Warnings
warning  To prevent hard-coded passwords, automatic remediation of this control is not available. Remediation must be automated as a component of machine provisioning, or followed manually as outlined above. Also, do NOT manually add the superuser account and password to the grub.cfg file as the grub2-mkconfig command overwrites this file.
Install systemd-journal-remote Packagexccdf_org.ssgproject.content_rule_package_systemd-journal-remote_installed medium

Install systemd-journal-remote Package

Rule IDxccdf_org.ssgproject.content_rule_package_systemd-journal-remote_installed
Result
pass
Time2024-04-05T12:58:37
Severitymedium
Identifiers and References

References:  4.2.1.1.1

Description

Journald (via systemd-journal-remote ) supports the ability to send log events it gathers to a remote log host or to receive messages from remote hosts, thus enabling centralised log management.

Rationale

Storing log data on a remote host protects log integrity from local attacks. If an attacker gains root access on the local system, they could tamper with or remove log data that is stored on the local system.

Enable systemd-journald Servicexccdf_org.ssgproject.content_rule_service_systemd-journald_enabled medium

Enable systemd-journald Service

Rule IDxccdf_org.ssgproject.content_rule_service_systemd-journald_enabled
Result
unknown
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  CCI-001665, SC-24, SRG-OS-000269-GPOS-00103, 4.2.1.2

Description

The systemd-journald service is an essential component of systemd. The systemd-journald service can be enabled with the following command:

$ sudo systemctl enable systemd-journald.service

Rationale

In the event of a system failure, Ubuntu 22.04 must preserve any information necessary to determine cause of failure and any information necessary to return to operations with least disruption to system processes.

Remediation Puppet snippet:   (show)

Complexity:low
Disruption:low
Strategy:enable
include enable_systemd-journald

class enable_systemd-journald {
  service {'systemd-journald':
    enable => true,
    ensure => 'running',
  }
}
Remediation Ansible snippet:   (show)

Complexity:low
Disruption:low
Strategy:enable
- name: Enable service systemd-journald
  block:

  - name: Gather the package facts
    package_facts:
      manager: auto

  - name: Enable service systemd-journald
    service:
      name: systemd-journald
      enabled: 'yes'
      state: started
      masked: 'no'
    when:
    - '"systemd" in ansible_facts.packages'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-SC-24
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_systemd-journald_enabled
Remediation Shell script:   (show)

Complexity:low
Disruption:low
Strategy:enable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'systemd-journald.service'
"$SYSTEMCTL_EXEC" start 'systemd-journald.service'
"$SYSTEMCTL_EXEC" enable 'systemd-journald.service'

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation script:   (show)


[customizations.services]
enabled = ["systemd-journald"]
Ensure journald is configured to compress large log filesxccdf_org.ssgproject.content_rule_journald_compress medium

Ensure journald is configured to compress large log files

Rule IDxccdf_org.ssgproject.content_rule_journald_compress
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  4.2.1.3

Description

The journald system can compress large log files to avoid fill the system disk.

Rationale

Log files that are not properly compressed run the risk of growing so large that they fill up the log partition. Valuable logging information could be lost if the log partition becomes full.

Ensure journald is configured to write log files to persistent diskxccdf_org.ssgproject.content_rule_journald_storage medium

Ensure journald is configured to write log files to persistent disk

Rule IDxccdf_org.ssgproject.content_rule_journald_storage
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  4.2.1.4

Description

The journald system may store log files in volatile memory or locally on disk. If the logs are only stored in volatile memory they will we lost upon reboot.

Rationale

Log files contain valuable data and need to be persistent to aid in possible investigations.

Disable systemd-journal-remote Socketxccdf_org.ssgproject.content_rule_socket_systemd-journal-remote_disabled medium

Disable systemd-journal-remote Socket

Rule IDxccdf_org.ssgproject.content_rule_socket_systemd-journal-remote_disabled
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  4.2.1.1.4

Description

Journald supports the ability to receive messages from remote hosts, thus acting as a log server. Clients should not receive data from other hosts. NOTE: The same package, systemd-journal-remote , is used for both sending logs to remote hosts and receiving incoming logs. With regards to receiving logs, there are two Systemd unit files; systemd-journal-remote.socket and systemd-journal-remote.service.

Rationale

If a client is configured to also receive data, thus turning it into a server, the client system is acting outside it's operational boundary.

Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Serverxccdf_org.ssgproject.content_rule_rsyslog_nolisten medium

Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server

Rule IDxccdf_org.ssgproject.content_rule_rsyslog_nolisten
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9, APO01.06, APO11.04, APO13.01, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02, MEA02.01, CCI-000318, CCI-000366, CCI-000368, CCI-001812, CCI-001813, CCI-001814, 4.2.3.4, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.8, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, 0988, 1405, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.5.1, A.12.6.2, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.IP-1, PR.PT-1, PR.PT-4, SRG-OS-000480-GPOS-00227, 4.2.2.7

Description

The rsyslog daemon should not accept remote messages unless the system acts as a log server. To ensure that it is not listening on the network, ensure the following lines are not found in /etc/rsyslog.conf:

$ModLoad imtcp
$InputTCPServerRun port
$ModLoad imudp
$UDPServerRun port
$ModLoad imrelp
$InputRELPServerRun port

Rationale

Any process which receives messages from the network incurs some risk of receiving malicious messages. This risk can be eliminated for rsyslog by configuring it not to listen on the network.

Ensure Logs Sent To Remote Hostxccdf_org.ssgproject.content_rule_rsyslog_remote_loghost medium

Ensure Logs Sent To Remote Host

Rule IDxccdf_org.ssgproject.content_rule_rsyslog_remote_loghost
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R7), NT28(R43), NT12(R5), 1, 13, 14, 15, 16, 2, 3, 5, 6, APO11.04, APO13.01, BAI03.05, BAI04.04, DSS05.04, DSS05.07, MEA02.01, CCI-000366, CCI-001348, CCI-000136, CCI-001851, 164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(B), 164.308(a)(5)(ii)(C), 164.308(a)(6)(ii), 164.308(a)(8), 164.310(d)(2)(iii), 164.312(b), 164.314(a)(2)(i)(C), 164.314(a)(2)(iii), 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 7.1, SR 7.2, 0988, 1405, A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.17.2.1, CIP-003-8 R5.2, CIP-004-6 R3.3, CM-6(a), AU-4(1), AU-9(2), PR.DS-4, PR.PT-1, FAU_GEN.1.1.c, SRG-OS-000479-GPOS-00224, SRG-OS-000480-GPOS-00227, SRG-OS-000342-GPOS-00133, 4.2.2.6

Description

To configure rsyslog to send logs to a remote log server, open /etc/rsyslog.conf and read and understand the last section of the file, which describes the multiple directives necessary to activate remote logging. Along with these other directives, the system can be configured to forward its logs to a particular log server by adding or correcting one of the following lines, substituting logcollector appropriately. The choice of protocol depends on the environment of the system; although TCP and RELP provide more reliable message delivery, they may not be supported in all environments.
To use UDP for log message delivery:

*.* @logcollector

To use TCP for log message delivery:
*.* @@logcollector

To use RELP for log message delivery:
*.* :omrelp:logcollector

There must be a resolvable DNS CNAME or Alias record set to "logcollector" for logs to be sent correctly to the centralized logging utility.

Rationale

A log server (loghost) receives syslog messages from one or more systems. This data can be used as an additional log source in the event a system is compromised and its local logs are suspect. Forwarding log messages to a remote loghost also provides system administrators with a centralized place to view the status of multiple hosts within the enterprise.

Warnings
warning  It is important to configure queues in case the client is sending log messages to a remote server. If queues are not configured, the system will stop functioning when the connection to the remote server is not available. Please consult Rsyslog documentation for more information about configuration of queues. The example configuration which should go into /etc/rsyslog.conf can look like the following lines:
$ActionQueueType LinkedList
$ActionQueueFileName queuefilename
$ActionQueueMaxDiskSpace 1g
$ActionQueueSaveOnShutdown on
$ActionResumeRetryCount -1
Ensure rsyslog is Installedxccdf_org.ssgproject.content_rule_package_rsyslog_installed medium

Ensure rsyslog is Installed

Rule IDxccdf_org.ssgproject.content_rule_package_rsyslog_installed
Result
pass
Time2024-04-05T12:58:27
Severitymedium
Identifiers and References

References:  BP28(R5), NT28(R46), 1, 14, 15, 16, 3, 5, 6, APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01, CCI-001311, CCI-001312, CCI-000366, 164.312(a)(2)(ii), 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, CM-6(a), PR.PT-1, FTP_ITC_EXT.1.1, SRG-OS-000479-GPOS-00224, SRG-OS-000051-GPOS-00024, SRG-OS-000480-GPOS-00227, 4.2.2.1

Description

Rsyslog is installed by default. The rsyslog package can be installed with the following command:

 $ apt-get install rsyslog

Rationale

The rsyslog package provides the rsyslog daemon, which provides system logging services.

Enable rsyslog Servicexccdf_org.ssgproject.content_rule_service_rsyslog_enabled medium

Enable rsyslog Service

Rule IDxccdf_org.ssgproject.content_rule_service_rsyslog_enabled
Result
unknown
Time2024-04-05T12:58:37
Severitymedium
Identifiers and References

References:  BP28(R5), NT28(R46), 1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO13.01, BAI03.05, BAI04.04, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01, CCI-001311, CCI-001312, CCI-001557, CCI-001851, CCI-000366, 164.312(a)(2)(ii), 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2, SR 7.1, SR 7.2, A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2, A.17.2.1, CM-6(a), AU-4(1), DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.DS-4, PR.PT-1, SRG-OS-000480-GPOS-00227, 4.2.2.2

Description

The rsyslog service provides syslog-style logging by default on Ubuntu 22.04. The rsyslog service can be enabled with the following command:

$ sudo systemctl enable rsyslog.service

Rationale

The rsyslog service must be running in order to provide logging services, which are essential to system administration.

Remediation Puppet snippet:   (show)

Complexity:low
Disruption:low
Strategy:enable
include enable_rsyslog

class enable_rsyslog {
  service {'rsyslog':
    enable => true,
    ensure => 'running',
  }
}
Remediation Ansible snippet:   (show)

Complexity:low
Disruption:low
Strategy:enable
- name: Enable service rsyslog
  block:

  - name: Gather the package facts
    package_facts:
      manager: auto

  - name: Enable service rsyslog
    service:
      name: rsyslog
      enabled: 'yes'
      state: started
      masked: 'no'
    when:
    - '"rsyslog" in ansible_facts.packages'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-AU-4(1)
  - NIST-800-53-CM-6(a)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_rsyslog_enabled
Remediation Shell script:   (show)

Complexity:low
Disruption:low
Strategy:enable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'rsyslog.service'
"$SYSTEMCTL_EXEC" start 'rsyslog.service'
"$SYSTEMCTL_EXEC" enable 'rsyslog.service'

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation script:   (show)


[customizations.services]
enabled = ["rsyslog"]
Ensure rsyslog Default File Permissions Configuredxccdf_org.ssgproject.content_rule_rsyslog_filecreatemode medium

Ensure rsyslog Default File Permissions Configured

Rule IDxccdf_org.ssgproject.content_rule_rsyslog_filecreatemode
Result
pass
Time2024-04-05T12:58:37
Severitymedium
Identifiers and References

References:  4.2.2.4

Description

rsyslog will create logfiles that do not already exist on the system. This settings controls what permissions will be applied to these newly created files.

Rationale

It is important to ensure that log files have the correct permissions to ensure that sensitive data is archived and protected.

Set Default ip6tables Policy for Incoming Packetsxccdf_org.ssgproject.content_rule_set_ip6tables_default_rule medium

Set Default ip6tables Policy for Incoming Packets

Rule IDxccdf_org.ssgproject.content_rule_set_ip6tables_default_rule
Result
notapplicable
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CIP-003-8 R4, CIP-003-8 R5, CIP-004-6 R3, AC-4, CM-7(b), CA-3(5), SC-7(21), CM-6(a), PR.IP-1, PR.PT-3, Req-1.4.1, 3.5.3.3.1

Description

To set the default policy to DROP (instead of ACCEPT) for the built-in INPUT chain which processes incoming packets, add or correct the following line in /etc/sysconfig/ip6tables:

:INPUT DROP [0:0]
If changes were required, reload the ip6tables rules:
$ sudo service ip6tables reload

Rationale

In ip6tables, the default policy is applied only after all the applicable rules in the table are examined for a match. Setting the default policy to DROP implements proper design for a firewall, i.e. any packets which are not explicitly permitted should not be accepted.

Set configuration for IPv6 loopback trafficxccdf_org.ssgproject.content_rule_set_ipv6_loopback_traffic medium

Set configuration for IPv6 loopback traffic

Rule IDxccdf_org.ssgproject.content_rule_set_ipv6_loopback_traffic
Result
notapplicable
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  Req-1.4.1, 3.5.3.3.2

Description

Configure the loopback interface to accept traffic. Configure all other interfaces to deny traffic to the loopback network.

Rationale

Loopback traffic is generated between processes on machine and is typically critical to operation of the system. The loopback interface is the only place that loopback network traffic should be seen, all other interfaces should ignore traffic on this network as an anti-spoofing measure.

Warnings
warning  Changing firewall settings while connected over network can result in being locked out of the system.
Set configuration for loopback trafficxccdf_org.ssgproject.content_rule_set_loopback_traffic medium

Set configuration for loopback traffic

Rule IDxccdf_org.ssgproject.content_rule_set_loopback_traffic
Result
notapplicable
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  Req-1.4.1, 3.5.3.2.2

Description

Configure the loopback interface to accept traffic. Configure all other interfaces to deny traffic to the loopback network.

Rationale

Loopback traffic is generated between processes on machine and is typically critical to operation of the system. The loopback interface is the only place that loopback network traffic should be seen, all other interfaces should ignore traffic on this network as an anti-spoofing measure.

Warnings
warning  Changing firewall settings while connected over network can result in being locked out of the system.
Ensure ip6tables Firewall Rules Exist for All Open Portsxccdf_org.ssgproject.content_rule_ip6tables_rules_for_open_ports medium

Ensure ip6tables Firewall Rules Exist for All Open Ports

Rule IDxccdf_org.ssgproject.content_rule_ip6tables_rules_for_open_ports
Result
notapplicable
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  3.5.3.3.4

Description

Any ports that have been opened on non-loopback addresses need firewall rules to govern traffic.

Rationale

Without a firewall rule configured for open ports default firewall policy will drop all packets to these ports.

Warnings
warning  Changing firewall settings while connected over network can result in being locked out of the system.
Ensure iptables Firewall Rules Exist for All Open Portsxccdf_org.ssgproject.content_rule_iptables_rules_for_open_ports medium

Ensure iptables Firewall Rules Exist for All Open Ports

Rule IDxccdf_org.ssgproject.content_rule_iptables_rules_for_open_ports
Result
notapplicable
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  3.5.3.2.4

Description

Any ports that have been opened on non-loopback addresses need firewall rules to govern traffic.

Rationale

Without a firewall rule configured for open ports default firewall policy will drop all packets to these ports.

Warnings
warning  Changing firewall settings while connected over network can result in being locked out of the system.
Set Default iptables Policy for Incoming Packetsxccdf_org.ssgproject.content_rule_set_iptables_default_rule medium

Set Default iptables Policy for Incoming Packets

Rule IDxccdf_org.ssgproject.content_rule_set_iptables_default_rule
Result
notapplicable
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CA-3(5), CM-7(b), SC-7(23), CM-6(a), PR.IP-1, PR.PT-3, 3.5.3.2.1

Description

To set the default policy to DROP (instead of ACCEPT) for the built-in INPUT chain which processes incoming packets, add or correct the following line in /etc/sysconfig/iptables:

:INPUT DROP [0:0]

Rationale

In iptables the default policy is applied only after all the applicable rules in the table are examined for a match. Setting the default policy to DROP implements proper design for a firewall, i.e. any packets which are not explicitly permitted should not be accepted.

Install iptables Packagexccdf_org.ssgproject.content_rule_package_iptables_installed medium

Install iptables Package

Rule IDxccdf_org.ssgproject.content_rule_package_iptables_installed
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  CM-6(a), Req-1.4.1, SRG-OS-000480-GPOS-00227, 3.5.3.1.1

Description

The iptables package can be installed with the following command:

$ apt-get install iptables

Rationale

iptables controls the Linux kernel network packet filtering code. iptables allows system operators to set up firewalls and IP masquerading, etc.

Remove iptables-persistent Packagexccdf_org.ssgproject.content_rule_package_iptables-persistent_removed medium

Remove iptables-persistent Package

Rule IDxccdf_org.ssgproject.content_rule_package_iptables-persistent_removed
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  3.5.1.2

Description

The iptables-persistent package can be removed with the following command:

$ apt-get remove iptables-persistent

Rationale

Running both ufw and the services included in the iptables-persistent package may lead to conflict.

Configure Accepting Router Advertisements on All IPv6 Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_ra medium

Configure Accepting Router Advertisements on All IPv6 Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_ra
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, 3.3.9

Description

To set the runtime status of the net.ipv6.conf.all.accept_ra kernel parameter, run the following command:

$ sudo sysctl -w net.ipv6.conf.all.accept_ra=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.all.accept_ra = 0

Rationale

An illicit router advertisement message could result in a man-in-the-middle attack.

Disable Accepting ICMP Redirects for All IPv6 Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_redirects medium

Disable Accepting ICMP Redirects for All IPv6 Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_redirects
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, 3.3.2

Description

To set the runtime status of the net.ipv6.conf.all.accept_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv6.conf.all.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.all.accept_redirects = 0

Rationale

An illicit ICMP redirect message could result in a man-in-the-middle attack.

Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_source_route medium

Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_source_route
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9, APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4, SRG-OS-000480-GPOS-00227, 3.3.1

Description

To set the runtime status of the net.ipv6.conf.all.accept_source_route kernel parameter, run the following command:

$ sudo sysctl -w net.ipv6.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.all.accept_source_route = 0

Rationale

Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and the system is functioning as a router.

Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required.

Disable Kernel Parameter for IPv6 Forwardingxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_forwarding medium

Disable Kernel Parameter for IPv6 Forwarding

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_forwarding
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv), DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, 3.2.2

Description

To set the runtime status of the net.ipv6.conf.all.forwarding kernel parameter, run the following command:

$ sudo sysctl -w net.ipv6.conf.all.forwarding=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.all.forwarding = 0

Rationale

IP forwarding permits the kernel to forward packets from one network interface to another. The ability to forward packets between two networks is only appropriate for systems acting as routers.

Disable Accepting Router Advertisements on all IPv6 Interfaces by Defaultxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_ra medium

Disable Accepting Router Advertisements on all IPv6 Interfaces by Default

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_ra
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, 3.3.9

Description

To set the runtime status of the net.ipv6.conf.default.accept_ra kernel parameter, run the following command:

$ sudo sysctl -w net.ipv6.conf.default.accept_ra=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.default.accept_ra = 0

Rationale

An illicit router advertisement message could result in a man-in-the-middle attack.

Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_redirects medium

Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_redirects
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, 3.3.2

Description

To set the runtime status of the net.ipv6.conf.default.accept_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv6.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.default.accept_redirects = 0

Rationale

An illicit ICMP redirect message could result in a man-in-the-middle attack.

Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces by Defaultxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_source_route medium

Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces by Default

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_source_route
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9, APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv), DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227, 3.3.1

Description

To set the runtime status of the net.ipv6.conf.default.accept_source_route kernel parameter, run the following command:

$ sudo sysctl -w net.ipv6.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv6.conf.default.accept_source_route = 0

Rationale

Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required.

Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_accept_source_route medium

Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_accept_source_route
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, 3.3.1

Description

To set the runtime status of the net.ipv4.conf.all.accept_source_route kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.accept_source_route = 0

Rationale

Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv4 forwarding is enabled and the system is functioning as a router.

Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required.

Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_log_martians unknown

Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_log_martians
Result
pass
Time2024-04-05T12:58:47
Severityunknown
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.04, DSS03.05, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.06, 3.1.20, CCI-000126, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.11.2.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), SC-5(3)(a), DE.CM-1, PR.AC-3, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, 3.3.4

Description

To set the runtime status of the net.ipv4.conf.all.log_martians kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.all.log_martians=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.log_martians = 1

Rationale

The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.

Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_rp_filter medium

Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_rp_filter
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, CCI-001551, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227, 3.3.7

Description

To set the runtime status of the net.ipv4.conf.all.rp_filter kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.all.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.rp_filter = 1

Rationale

Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.

Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_secure_redirects medium

Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_secure_redirects
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-001503, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227, 3.3.3

Description

To set the runtime status of the net.ipv4.conf.all.secure_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.all.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.secure_redirects = 0

Rationale

Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.

Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_accept_redirects medium

Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_accept_redirects
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227, 3.3.2

Description

To set the runtime status of the net.ipv4.conf.default.accept_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.accept_redirects = 0

Rationale

ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack.
This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required.

Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces by Defaultxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_accept_source_route medium

Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces by Default

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_accept_source_route
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, 3.3.1

Description

To set the runtime status of the net.ipv4.conf.default.accept_source_route kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.accept_source_route = 0

Rationale

Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures.
Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required, such as when IPv4 forwarding is enabled and the system is legitimately functioning as a router.

Enable Kernel Paremeter to Log Martian Packets on all IPv4 Interfaces by Defaultxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_log_martians unknown

Enable Kernel Paremeter to Log Martian Packets on all IPv4 Interfaces by Default

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_log_martians
Result
pass
Time2024-04-05T12:58:47
Severityunknown
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.04, DSS03.05, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.06, 3.1.20, CCI-000126, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.11.2.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), SC-5(3)(a), DE.CM-1, PR.AC-3, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, 3.3.4

Description

To set the runtime status of the net.ipv4.conf.default.log_martians kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.default.log_martians=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.log_martians = 1

Rationale

The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.

Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces by Defaultxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_rp_filter medium

Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces by Default

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_rp_filter
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4, SRG-OS-000480-GPOS-00227, 3.3.7

Description

To set the runtime status of the net.ipv4.conf.default.rp_filter kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.default.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.rp_filter = 1

Rationale

Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.

Configure Kernel Parameter for Accepting Secure Redirects By Defaultxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_secure_redirects medium

Configure Kernel Parameter for Accepting Secure Redirects By Default

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_secure_redirects
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-001551, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, 3.3.3

Description

To set the runtime status of the net.ipv4.conf.default.secure_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.default.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.secure_redirects = 0

Rationale

Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.

Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_icmp_echo_ignore_broadcasts medium

Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_icmp_echo_ignore_broadcasts
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.4.3, SRG-OS-000480-GPOS-00227, 3.3.5

Description

To set the runtime status of the net.ipv4.icmp_echo_ignore_broadcasts kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.icmp_echo_ignore_broadcasts = 1

Rationale

Responding to broadcast (ICMP) echoes facilitates network mapping and provides a vector for amplification attacks.
Ignoring ICMP echo requests (pings) sent to broadcast or multicast addresses makes the system slightly more difficult to enumerate on the network.

Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_icmp_ignore_bogus_error_responses unknown

Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_icmp_ignore_bogus_error_responses
Result
pass
Time2024-04-05T12:58:47
Severityunknown
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 3.1.20, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, Req-1.4.3, SRG-OS-000480-GPOS-00227, 3.3.6

Description

To set the runtime status of the net.ipv4.icmp_ignore_bogus_error_responses kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.icmp_ignore_bogus_error_responses = 1

Rationale

Ignoring bogus ICMP error responses reduces log size, although some activity would not be logged.

Enable Kernel Parameter to Use TCP Syncookies on Network Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_tcp_syncookies medium

Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_tcp_syncookies
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02, 3.1.20, CCI-000366, CCI-001095, 4.2.3.4, 4.3.3.4, 4.4.3.3, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-7(a), CM-7(b), SC-5(1), SC-5(2), SC-5(3)(a), CM-6(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4, Req-1.4.1, SRG-OS-000480-GPOS-00227, SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00071, 3.3.8

Description

To set the runtime status of the net.ipv4.tcp_syncookies kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.tcp_syncookies=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.tcp_syncookies = 1

Rationale

A TCP SYN flood attack can cause a denial of service by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies can be used to track a connection when a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This feature is activated when a flood condition is detected, and enables the system to continue servicing valid connection requests.

Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_send_redirects medium

Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_send_redirects
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, 3.2.1

Description

To set the runtime status of the net.ipv4.conf.all.send_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.all.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.all.send_redirects = 0

Rationale

ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology.
The ability to send ICMP redirects is only appropriate for systems acting as routers.

Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces by Defaultxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_send_redirects medium

Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces by Default

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_send_redirects
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9, 5.10.1.1, APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, 3.1.20, CCI-000366, 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4, SRG-OS-000480-GPOS-00227, 3.2.1

Description

To set the runtime status of the net.ipv4.conf.default.send_redirects kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.conf.default.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.conf.default.send_redirects = 0

Rationale

ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology.
The ability to send ICMP redirects is only appropriate for systems acting as routers.

Disable Kernel Parameter for IP Forwarding on IPv4 Interfacesxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_ip_forward medium

Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces

Rule IDxccdf_org.ssgproject.content_rule_sysctl_net_ipv4_ip_forward
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  BP28(R22), 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06, 3.1.20, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1, CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a), DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.3.1, Req-1.3.2, SRG-OS-000480-GPOS-00227, 3.2.2

Description

To set the runtime status of the net.ipv4.ip_forward kernel parameter, run the following command:

$ sudo sysctl -w net.ipv4.ip_forward=0
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
net.ipv4.ip_forward = 0

Rationale

Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this capability is used when not required, system network information may be unnecessarily transmitted across the network.

Warnings
warning  Certain technologies such as virtual machines, containers, etc. rely on IPv4 forwarding to enable and use networking. Disabling IPv4 forwarding would cause those technologies to stop working. Therefore, this rule should not be used in profiles or benchmarks that target usage of IPv4 forwarding.
Install nftables Packagexccdf_org.ssgproject.content_rule_package_nftables_installed medium

Install nftables Package

Rule IDxccdf_org.ssgproject.content_rule_package_nftables_installed
Result
pass
Time2024-04-05T12:58:47
Severitymedium
Identifiers and References

References:  3.5.2.1

Description

nftables provides a new in-kernel packet classification framework that is based on a network-specific Virtual Machine (VM) and a new nft userspace command line tool. nftables reuses the existing Netfilter subsystems such as the existing hook infrastructure, the connection tracking system, NAT, userspace queuing and logging subsystem. The nftables package can be installed with the following command:

$ apt-get install nftables

Rationale

nftables is a subsystem of the Linux kernel that can protect against threats originating from within a corporate network to include malicious mobile code and poorly configured software on a host.

Verify nftables Service is Enabledxccdf_org.ssgproject.content_rule_service_nftables_enabled medium

Verify nftables Service is Enabled

Rule IDxccdf_org.ssgproject.content_rule_service_nftables_enabled
Result
unknown
Time2024-04-05T12:58:57
Severitymedium
Identifiers and References

References:  3.5.2.9

Description

The nftables service allows for the loading of nftables rulesets during boot, or starting on the nftables service The nftables service can be enabled with the following command:

$ sudo systemctl enable nftables.service

Rationale

The nftables service restores the nftables rules from the rules files referenced in the /etc/sysconfig/nftables.conf file during boot or the starting of the nftables service

Remediation Puppet snippet:   (show)

Complexity:low
Disruption:low
Strategy:enable
include enable_nftables

class enable_nftables {
  service {'nftables':
    enable => true,
    ensure => 'running',
  }
}
Remediation Ansible snippet:   (show)

Complexity:low
Disruption:low
Strategy:enable
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_nftables_enabled

- name: Enable service nftables
  block:

  - name: Gather the package facts
    package_facts:
      manager: auto

  - name: Enable service nftables
    service:
      name: nftables
      enabled: 'yes'
      state: started
      masked: 'no'
    when:
    - '"nftables" in ansible_facts.packages'
  when: '"nftables" in ansible_facts.packages'
  tags:
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_nftables_enabled
Remediation Shell script:   (show)

Complexity:low
Disruption:low
Strategy:enable
# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}\n' 'nftables' 2>/dev/null | grep -q installed; then

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'nftables.service'
"$SYSTEMCTL_EXEC" start 'nftables.service'
"$SYSTEMCTL_EXEC" enable 'nftables.service'

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation script:   (show)


[customizations.services]
enabled = ["nftables"]
Ensure nftables rules are permanentxccdf_org.ssgproject.content_rule_nftables_rules_permanent medium

Ensure nftables rules are permanent

Rule IDxccdf_org.ssgproject.content_rule_nftables_rules_permanent
Result
pass
Time2024-04-05T12:58:57
Severitymedium
Identifiers and References

References:  3.5.2.10

Description

nftables is a subsystem of the Linux kernel providing filtering and classification of network packets/datagrams/frames. The nftables service reads the /etc/nftables.conf file for a nftables file or files to include in the nftables ruleset. A nftables ruleset containing the input, forward, and output base chains allow network traffic to be filtered.

Rationale

Changes made to nftables ruleset only affect the live system, you will also need to configure the nftables ruleset to apply on boot

Ensure Base Chains Exist for Nftablesxccdf_org.ssgproject.content_rule_set_nftables_base_chain medium

Ensure Base Chains Exist for Nftables

Rule IDxccdf_org.ssgproject.content_rule_set_nftables_base_chain
Result
pass
Time2024-04-05T12:58:57
Severitymedium
Identifiers and References

References:  3.5.2.5

Description

Tables in nftables hold chains. Each table only has one address family and only applies to packets of this family. Tables can have one of six families. Chains are containers for rules. They exist in two kinds, base chains and regular chains. A base chain is an entry point for packets from the networking stack, a regular chain may be used as jump target and is used for better rule organization.

Rationale

If a base chain doesn't exist with a hook for input, forward, and delete, packets that would flow through those chains will not be touched by nftables.

Warnings
warning  Configuring rules over ssh, by creating a base chain with policy drop will cause loss of connectivity. Ensure that a rule allowing ssh has been added to the base chain prior to setting the base cahin's policy to drop
Set nftables configuration for loopback trafficxccdf_org.ssgproject.content_rule_set_nftables_loopback_traffic medium

Set nftables configuration for loopback traffic

Rule IDxccdf_org.ssgproject.content_rule_set_nftables_loopback_traffic
Result
pass
Time2024-04-05T12:58:57
Severitymedium
Identifiers and References

References:  Req-1.4.1, 3.5.2.6

Description

Configure the loopback interface to accept traffic. Configure all other interfaces to deny traffic to the loopback network.

Rationale

Loopback traffic is generated between processes on machine and is typically critical to operation of the system. The loopback interface is the only place that loopback network traffic should be seen, all other interfaces should ignore traffic on this network as an anti-spoofing measure.

Warnings
warning  Changing firewall settings while connected over network can result in being locked out of the system.
Ensure a Table Exists for Nftablesxccdf_org.ssgproject.content_rule_set_nftables_table medium

Ensure a Table Exists for Nftables

Rule IDxccdf_org.ssgproject.content_rule_set_nftables_table
Result
pass
Time2024-04-05T12:58:57
Severitymedium
Identifiers and References

References:  3.5.2.4

Description

Tables in nftables hold chains. Each table only has one address family and only applies to packets of this family. Tables can have one of six families.

Rationale

Nftables doesn't have any default tables. Without a table being built, nftables will not filter network traffic. Note: adding rules to a running nftables can cause loss of connectivity to the system.

Warnings
warning  Adding rules to a running nftables can cause loss of connectivity to the system.
Remove ufw Packagexccdf_org.ssgproject.content_rule_package_ufw_removed medium

Remove ufw Package

Rule IDxccdf_org.ssgproject.content_rule_package_ufw_removed
Result
pass
Time2024-04-05T12:58:57
Severitymedium
Identifiers and References

References:  3.5.3.1.3

Description

The ufw package can be removed with the following command:

$ apt-get remove ufw

Rationale

Running iptables.persistent with ufw enabled may lead to conflict and unexpected results.

Verify ufw Enabledxccdf_org.ssgproject.content_rule_service_ufw_enabled medium

Verify ufw Enabled

Rule IDxccdf_org.ssgproject.content_rule_service_ufw_enabled
Result
notapplicable
Time2024-04-05T12:58:57
Severitymedium
Identifiers and References

References:  CCI-002314, SRG-OS-000297-GPOS-00115, 3.5.1.3

Description

The ufw service can be enabled with the following command:

$ sudo systemctl enable ufw.service

Rationale

The ufw service must be enabled and running in order for ufw to protect the system

Ensure ufw Default Deny Firewall Policyxccdf_org.ssgproject.content_rule_set_ufw_default_rule medium

Ensure ufw Default Deny Firewall Policy

Rule IDxccdf_org.ssgproject.content_rule_set_ufw_default_rule
Result
notapplicable
Time2024-04-05T12:58:57
Severitymedium
Identifiers and References

References:  3.5.1.7

Description

A default deny policy on connections ensures that any unconfigured network usage will be rejected. Note: Any port or protocol without a explicit allow before the default deny will be blocked.

Rationale

With a default accept policy the firewall will accept any packet that is not configured to be denied. It is easier to allow acceptable usage than to block unacceptable usage.

Warnings
warning  Changing firewall settings while connected over network can result in being locked out of the system.
Set UFW Loopback Trafficxccdf_org.ssgproject.content_rule_set_ufw_loopback_traffic medium

Set UFW Loopback Traffic

Rule IDxccdf_org.ssgproject.content_rule_set_ufw_loopback_traffic
Result
notapplicable
Time2024-04-05T12:58:57
Severitymedium
Identifiers and References

References:  3.5.1.4

Description

Configure the loopback interface to accept traffic. Configure all other interfaces to deny traffic to the loopback network.

Rationale

Loopback traffic is generated between processes on machine and is typically critical to operation of the system. The loopback interface is the only place that loopback network traffic should be seen, all other interfaces should ignore traffic on this network as an anti-spoofing measure.

Warnings
warning  Changing firewall settings while connected over network can result in being locked out of the system.
Ensure ufw Firewall Rules Exist for All Open Portsxccdf_org.ssgproject.content_rule_ufw_rules_for_open_ports medium

Ensure ufw Firewall Rules Exist for All Open Ports

Rule IDxccdf_org.ssgproject.content_rule_ufw_rules_for_open_ports
Result
notapplicable
Time2024-04-05T12:58:57
Severitymedium
Identifiers and References

References:  3.5.1.6

Description

Any ports that have been opened on non-loopback addresses need firewall rules to govern traffic.

Rationale

Without a firewall rule configured for open ports default firewall policy will drop all packets to these ports.

Warnings
warning  Changing firewall settings while connected over network can result in being locked out of the system.
Deactivate Wireless Network Interfacesxccdf_org.ssgproject.content_rule_wireless_disable_interfaces medium

Deactivate Wireless Network Interfaces

Rule IDxccdf_org.ssgproject.content_rule_wireless_disable_interfaces
Result
pass
Time2024-04-05T12:58:57
Severitymedium
Identifiers and References

References:  11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, 3.1.16, CCI-000085, CCI-002418, CCI-002421, CCI-001443, CCI-001444, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, 1315, 1319, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, AC-18(a), AC-18(3), CM-7(a), CM-7(b), CM-6(a), MP-7, PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, Req-1.3.3, SRG-OS-000299-GPOS-00117, SRG-OS-000300-GPOS-00118, SRG-OS-000424-GPOS-00188, SRG-OS-000481-GPOS-000481, 3.1.2

Description

Deactivating wireless network interfaces should prevent normal usage of the wireless capability.

Configure the system to disable all wireless network interfaces with the following command:

$ sudo nmcli radio all off

Rationale

The use of wireless networking can introduce many different attack vectors into the organization's network. Common attack vectors such as malicious association and ad hoc networks will allow an attacker to spoof a wireless access point (AP), allowing validated systems to connect to the malicious AP and enabling the attacker to monitor and record network traffic. These malicious APs can also serve to create a man-in-the-middle attack or be used to create a denial of service to valid network resources.

Verify Group Who Owns Backup group Filexccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_group medium

Verify Group Who Owns Backup group File

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_group
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-002223, AC-6 (1), SRG-OS-000480-GPOS-00227, 6.1.4

Description

To properly set the group owner of /etc/group-, run the command:

$ sudo chgrp root /etc/group-

Rationale

The /etc/group- file is a backup file of /etc/group, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Verify Group Who Owns Backup gshadow Filexccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_gshadow medium

Verify Group Who Owns Backup gshadow File

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_gshadow
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-002223, AC-6 (1), SRG-OS-000480-GPOS-00227, 6.1.8

Description

To properly set the group owner of /etc/gshadow-, run the command:

$ sudo chgrp shadow /etc/gshadow-

Rationale

The /etc/gshadow- file is a backup of /etc/gshadow, and as such, it contains group password hashes. Protection of this file is critical for system security.

Verify Group Who Owns Backup passwd Filexccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_passwd medium

Verify Group Who Owns Backup passwd File

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_passwd
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-002223, AC-6 (1), SRG-OS-000480-GPOS-00227, 6.1.2

Description

To properly set the group owner of /etc/passwd-, run the command:

$ sudo chgrp root /etc/passwd-

Rationale

The /etc/passwd- file is a backup file of /etc/passwd, and as such, it contains information about the users that are configured on the system. Protection of this file is critical for system security.

Verify User Who Owns Backup shadow Filexccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_shadow medium

Verify User Who Owns Backup shadow File

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_shadow
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  SRG-OS-000480-GPOS-00227, 6.1.6

Description

To properly set the group owner of /etc/shadow-, run the command:

$ sudo chgrp shadow /etc/shadow-

Rationale

The /etc/shadow- file is a backup file of /etc/shadow, and as such, it contains the list of local system accounts and password hashes. Protection of this file is critical for system security.

Verify Group Who Owns group Filexccdf_org.ssgproject.content_rule_file_groupowner_etc_group medium

Verify Group Who Owns group File

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_etc_group
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.3

Description

To properly set the group owner of /etc/group, run the command:

$ sudo chgrp root /etc/group

Rationale

The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Verify Group Who Owns gshadow Filexccdf_org.ssgproject.content_rule_file_groupowner_etc_gshadow medium

Verify Group Who Owns gshadow File

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_etc_gshadow
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 6.1.7

Description

To properly set the group owner of /etc/gshadow, run the command:

$ sudo chgrp shadow /etc/gshadow

Rationale

The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.

Verify Group Who Owns passwd Filexccdf_org.ssgproject.content_rule_file_groupowner_etc_passwd medium

Verify Group Who Owns passwd File

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_etc_passwd
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.1

Description

To properly set the group owner of /etc/passwd, run the command:

$ sudo chgrp root /etc/passwd

Rationale

The /etc/passwd file contains information about the users that are configured on the system. Protection of this file is critical for system security.

Verify Group Who Owns shadow Filexccdf_org.ssgproject.content_rule_file_groupowner_etc_shadow medium

Verify Group Who Owns shadow File

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_etc_shadow
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.5

Description

To properly set the group owner of /etc/shadow, run the command:

$ sudo chgrp shadow /etc/shadow

Rationale

The /etc/shadow file stores password hashes. Protection of this file is critical for system security.

Verify User Who Owns Backup group Filexccdf_org.ssgproject.content_rule_file_owner_backup_etc_group medium

Verify User Who Owns Backup group File

Rule IDxccdf_org.ssgproject.content_rule_file_owner_backup_etc_group
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-002223, AC-6 (1), SRG-OS-000480-GPOS-00227, 6.1.4

Description

To properly set the owner of /etc/group-, run the command:

$ sudo chown root /etc/group- 

Rationale

The /etc/group- file is a backup file of /etc/group, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Verify User Who Owns Backup gshadow Filexccdf_org.ssgproject.content_rule_file_owner_backup_etc_gshadow medium

Verify User Who Owns Backup gshadow File

Rule IDxccdf_org.ssgproject.content_rule_file_owner_backup_etc_gshadow
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-002223, AC-6 (1), SRG-OS-000480-GPOS-00227, 6.1.8

Description

To properly set the owner of /etc/gshadow-, run the command:

$ sudo chown root /etc/gshadow- 

Rationale

The /etc/gshadow- file is a backup of /etc/gshadow, and as such, it contains group password hashes. Protection of this file is critical for system security.

Verify User Who Owns Backup passwd Filexccdf_org.ssgproject.content_rule_file_owner_backup_etc_passwd medium

Verify User Who Owns Backup passwd File

Rule IDxccdf_org.ssgproject.content_rule_file_owner_backup_etc_passwd
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-002223, AC-6 (1), SRG-OS-000480-GPOS-00227, 6.1.2

Description

To properly set the owner of /etc/passwd-, run the command:

$ sudo chown root /etc/passwd- 

Rationale

The /etc/passwd- file is a backup file of /etc/passwd, and as such, it contains information about the users that are configured on the system. Protection of this file is critical for system security.

Verify Group Who Owns Backup shadow Filexccdf_org.ssgproject.content_rule_file_owner_backup_etc_shadow medium

Verify Group Who Owns Backup shadow File

Rule IDxccdf_org.ssgproject.content_rule_file_owner_backup_etc_shadow
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-002223, AC-6 (1), SRG-OS-000480-GPOS-00227, 6.1.6

Description

To properly set the owner of /etc/shadow-, run the command:

$ sudo chown root /etc/shadow- 

Rationale

The /etc/shadow- file is a backup file of /etc/shadow, and as such, it contains the list of local system accounts and password hashes. Protection of this file is critical for system security.

Verify User Who Owns group Filexccdf_org.ssgproject.content_rule_file_owner_etc_group medium

Verify User Who Owns group File

Rule IDxccdf_org.ssgproject.content_rule_file_owner_etc_group
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.3

Description

To properly set the owner of /etc/group, run the command:

$ sudo chown root /etc/group 

Rationale

The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Verify User Who Owns gshadow Filexccdf_org.ssgproject.content_rule_file_owner_etc_gshadow medium

Verify User Who Owns gshadow File

Rule IDxccdf_org.ssgproject.content_rule_file_owner_etc_gshadow
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 6.1.7

Description

To properly set the owner of /etc/gshadow, run the command:

$ sudo chown root /etc/gshadow 

Rationale

The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.

Verify User Who Owns passwd Filexccdf_org.ssgproject.content_rule_file_owner_etc_passwd medium

Verify User Who Owns passwd File

Rule IDxccdf_org.ssgproject.content_rule_file_owner_etc_passwd
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.1

Description

To properly set the owner of /etc/passwd, run the command:

$ sudo chown root /etc/passwd 

Rationale

The /etc/passwd file contains information about the users that are configured on the system. Protection of this file is critical for system security.

Verify User Who Owns shadow Filexccdf_org.ssgproject.content_rule_file_owner_etc_shadow medium

Verify User Who Owns shadow File

Rule IDxccdf_org.ssgproject.content_rule_file_owner_etc_shadow
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.5

Description

To properly set the owner of /etc/shadow, run the command:

$ sudo chown root /etc/shadow 

Rationale

The /etc/shadow file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.

Verify Permissions on Backup group Filexccdf_org.ssgproject.content_rule_file_permissions_backup_etc_group medium

Verify Permissions on Backup group File

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_backup_etc_group
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-002223, AC-6 (1), SRG-OS-000480-GPOS-00227, 6.1.4

Description

To properly set the permissions of /etc/group-, run the command:

$ sudo chmod 0644 /etc/group-

Rationale

The /etc/group- file is a backup file of /etc/group, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Verify Permissions on Backup gshadow Filexccdf_org.ssgproject.content_rule_file_permissions_backup_etc_gshadow medium

Verify Permissions on Backup gshadow File

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_backup_etc_gshadow
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-002223, AC-6 (1), SRG-OS-000480-GPOS-00227, 6.1.8

Description

To properly set the permissions of /etc/gshadow-, run the command:

$ sudo chmod 0640 /etc/gshadow-

Rationale

The /etc/gshadow- file is a backup of /etc/gshadow, and as such, it contains group password hashes. Protection of this file is critical for system security.

Verify Permissions on Backup passwd Filexccdf_org.ssgproject.content_rule_file_permissions_backup_etc_passwd medium

Verify Permissions on Backup passwd File

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_backup_etc_passwd
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-002223, AC-6 (1), SRG-OS-000480-GPOS-00227, 6.1.2

Description

To properly set the permissions of /etc/passwd-, run the command:

$ sudo chmod 0644 /etc/passwd-

Rationale

The /etc/passwd- file is a backup file of /etc/passwd, and as such, it contains information about the users that are configured on the system. Protection of this file is critical for system security.

Verify Permissions on Backup shadow Filexccdf_org.ssgproject.content_rule_file_permissions_backup_etc_shadow medium

Verify Permissions on Backup shadow File

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_backup_etc_shadow
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-002223, AC-6 (1), SRG-OS-000480-GPOS-00227, 6.1.6

Description

To properly set the permissions of /etc/shadow-, run the command:

$ sudo chmod 0640 /etc/shadow-

Rationale

The /etc/shadow- file is a backup file of /etc/shadow, and as such, it contains the list of local system accounts and password hashes. Protection of this file is critical for system security.

Verify Permissions on group Filexccdf_org.ssgproject.content_rule_file_permissions_etc_group medium

Verify Permissions on group File

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_etc_group
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.3

Description

To properly set the permissions of /etc/passwd, run the command:

$ sudo chmod 0644 /etc/passwd

Rationale

The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Verify Permissions on gshadow Filexccdf_org.ssgproject.content_rule_file_permissions_etc_gshadow medium

Verify Permissions on gshadow File

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_etc_gshadow
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 6.1.7

Description

To properly set the permissions of /etc/gshadow, run the command:

$ sudo chmod 0640 /etc/gshadow

Rationale

The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.

Verify Permissions on passwd Filexccdf_org.ssgproject.content_rule_file_permissions_etc_passwd medium

Verify Permissions on passwd File

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_etc_passwd
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.1

Description

To properly set the permissions of /etc/passwd, run the command:

$ sudo chmod 0644 /etc/passwd

Rationale

If the /etc/passwd file is writable by a group-owner or the world the risk of its compromise is increased. The file contains the list of accounts on the system and associated information, and protection of this file is critical for system security.

Verify Permissions on shadow Filexccdf_org.ssgproject.content_rule_file_permissions_etc_shadow medium

Verify Permissions on shadow File

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_etc_shadow
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, 5.5.2.2, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-002223, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-8.7.c, SRG-OS-000480-GPOS-00227, 6.1.5

Description

To properly set the permissions of /etc/shadow, run the command:

$ sudo chmod 0640 /etc/shadow

Rationale

The /etc/shadow file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.

Verify that audit tools are owned by group rootxccdf_org.ssgproject.content_rule_file_groupownership_audit_binaries medium

Verify that audit tools are owned by group root

Rule IDxccdf_org.ssgproject.content_rule_file_groupownership_audit_binaries
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-001493, CCI-001494, SRG-OS-000256-GPiOS-00097, SRG-OS-000257-GPOS-00098, 4.1.4.10

Description

The Ubuntu 22.04 operating system audit tools must have the proper ownership configured to protected against unauthorized access. Verify it by running the following command:

$ stat -c "%n %G" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/audispd /sbin/augenrules

/sbin/auditctl root
/sbin/aureport root
/sbin/ausearch root
/sbin/autrace root
/sbin/auditd root
/sbin/audispd root
/sbin/augenrules root
Audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators

Rationale

Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. Operating systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys to make access decisions regarding the access to audit tools.

Verify that audit tools are owned by rootxccdf_org.ssgproject.content_rule_file_ownership_audit_binaries medium

Verify that audit tools are owned by root

Rule IDxccdf_org.ssgproject.content_rule_file_ownership_audit_binaries
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-001493, CCI-001494, SRG-OS-000256-GPiOS-00097, SRG-OS-000257-GPOS-00098, 4.1.4.9

Description

The Ubuntu 22.04 operating system audit tools must have the proper ownership configured to protected against unauthorized access. Verify it by running the following command:

$ stat -c "%n %U" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/audispd /sbin/augenrules

/sbin/auditctl root
/sbin/aureport root
/sbin/ausearch root
/sbin/autrace root
/sbin/auditd root
/sbin/audispd root
/sbin/augenrules root
Audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators

Rationale

Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. Operating systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys to make access decisions regarding the access to audit tools.

Verify that audit tools Have Mode 0755 or lessxccdf_org.ssgproject.content_rule_file_permissions_audit_binaries medium

Verify that audit tools Have Mode 0755 or less

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_audit_binaries
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-001493, CCI-001494, SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098, 4.1.4.8

Description

The Ubuntu 22.04 operating system audit tools must have the proper permissions configured to protected against unauthorized access. Verify it by running the following command:

$ stat -c "%n %a" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/audispd /sbin/augenrules

/sbin/auditctl 755
/sbin/aureport 755
/sbin/ausearch 755
/sbin/autrace 755
/sbin/auditd 755
/sbin/audispd 755
/sbin/augenrules 755
Audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators

Rationale

Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. Operating systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys to make access decisions regarding the access to audit tools.

Verify Permissions on /etc/audit/auditd.confxccdf_org.ssgproject.content_rule_file_permissions_etc_audit_auditd medium

Verify Permissions on /etc/audit/auditd.conf

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_etc_audit_auditd
Result
pass
Time2024-04-05T12:58:57
Severitymedium
Identifiers and References

References:  CCI-000171, AU-12(b), SRG-OS-000063-GPOS-00032, 4.1.4.5

Description

To properly set the permissions of /etc/audit/auditd.conf, run the command:

$ sudo chmod 0640 /etc/audit/auditd.conf

Rationale

Without the capability to restrict the roles and individuals that can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.

Verify Permissions on /etc/audit/rules.d/*.rulesxccdf_org.ssgproject.content_rule_file_permissions_etc_audit_rulesd medium

Verify Permissions on /etc/audit/rules.d/*.rules

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_etc_audit_rulesd
Result
pass
Time2024-04-05T12:58:57
Severitymedium
Identifiers and References

References:  CCI-000171, AU-12(b), SRG-OS-000063-GPOS-00032, 4.1.4.5

Description

To properly set the permissions of /etc/audit/rules.d/*.rules, run the command:

$ sudo chmod 0640 /etc/audit/rules.d/*.rules

Rationale

Without the capability to restrict the roles and individuals that can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.

Ensure No World-Writable Files Existxccdf_org.ssgproject.content_rule_file_permissions_unauthorized_world_writable medium

Ensure No World-Writable Files Exist

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_unauthorized_world_writable
Result
pass
Time2024-04-05T12:59:02
Severitymedium
Identifiers and References

References:  BP28(R40), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, 6.1.9

Description

It is generally a good idea to remove global (other) write access to a file when it is discovered. However, check with documentation for specific applications before making changes. Also, monitor for recurring world-writable files, as these may be symptoms of a misconfigured application or user account. Finally, this applies to real files and not virtual files that are a part of pseudo file systems such as sysfs or procfs.

Rationale

Data in world-writable files can be modified by any user on the system. In almost all circumstances, files can be configured using a combination of user and group permissions to support whatever legitimate access is needed without the risk caused by world-writable files.

Ensure All Files Are Owned by a Groupxccdf_org.ssgproject.content_rule_file_permissions_ungroupowned medium

Ensure All Files Are Owned by a Group

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_ungroupowned
Result
pass
Time2024-04-05T12:59:07
Severitymedium
Identifiers and References

References:  1, 11, 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.06, DSS06.10, CCI-000366, CCI-002165, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, PR.PT-3, SRG-OS-000480-GPOS-00227, 6.1.11

Description

If any files are not owned by a group, then the cause of their lack of group-ownership should be investigated. Following this, the files should be deleted or assigned to an appropriate group. The following command will discover and print any files on local partitions which do not belong to a valid group:

$ df --local -P | awk '{if (NR!=1) print $6}' | sudo xargs -I '{}' find '{}' -xdev -nogroup
To search all filesystems on a system including network mounted filesystems the following command can be run manually for each partition:
$ sudo find PARTITION -xdev -nogroup

Rationale

Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed.

Warnings
warning  This rule only considers local groups. If you have your groups defined outside /etc/group, the rule won't consider those.
Ensure All Files Are Owned by a Userxccdf_org.ssgproject.content_rule_no_files_unowned_by_user medium

Ensure All Files Are Owned by a User

Rule IDxccdf_org.ssgproject.content_rule_no_files_unowned_by_user
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  11, 12, 13, 14, 15, 16, 18, 3, 5, 9, APO01.06, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, CCI-000366, CCI-002165, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.AC-6, PR.DS-5, PR.IP-1, PR.PT-3, SRG-OS-000480-GPOS-00227, 6.1.10

Description

If any files are not owned by a user, then the cause of their lack of ownership should be investigated. Following this, the files should be deleted or assigned to an appropriate user. The following command will discover and print any files on local partitions which do not belong to a valid user:

$ df --local -P | awk {'if (NR!=1) print $6'} | sudo xargs -I '{}' find '{}' -xdev -nouser
To search all filesystems on a system including network mounted filesystems the following command can be run manually for each partition:
$ sudo find PARTITION -xdev -nouser

Rationale

Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed.

Warnings
warning  For this rule to evaluate centralized user accounts, getent must be working properly so that running the command
getent passwd
returns a list of all users in your organization. If using the System Security Services Daemon (SSSD),
enumerate = true
must be configured in your organization's domain to return a complete list of users
warning  Enabling this rule will result in slower scan times depending on the size of your organization and number of centralized users.
Verify permissions of log filesxccdf_org.ssgproject.content_rule_permissions_local_var_log medium

Verify permissions of log files

Rule IDxccdf_org.ssgproject.content_rule_permissions_local_var_log
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-001312, SI-11(a), SI-11(b), SI-11.1(iii), PR.AC-4, PR.DS-5, SRG-OS-000205-GPOS-00083, 4.2.3

Description

Any operating system providing too much information in error messages risks compromising the data and security of the structure, and content of error messages needs to be carefully considered by the organization. Organizations carefully consider the structure/content of error messages. The extent to which information systems are able to identify and handle error conditions is guided by organizational policy and operational requirements. Information that could be exploited by adversaries includes, for example, erroneous logon attempts with passwords entered by mistake as the username, mission/business information that can be derived from (if not stated explicitly by) information recorded, and personal information, such as account numbers, social security numbers, and credit card numbers.

Rationale

The Ubuntu 22.04 must generate error messages that provide information necessary for corrective actions without revealing information that could be exploited by adversaries.

Disable the Automounterxccdf_org.ssgproject.content_rule_service_autofs_disabled medium

Disable the Automounter

Rule IDxccdf_org.ssgproject.content_rule_service_autofs_disabled
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  1, 12, 15, 16, 5, APO13.01, DSS01.04, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.4.6, CCI-000366, CCI-000778, CCI-001958, 164.308(a)(3)(i), 164.308(a)(3)(ii)(A), 164.310(d)(1), 164.310(d)(2), 164.312(a)(1), 164.312(a)(2)(iv), 164.312(b), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.6, A.11.2.6, A.13.1.1, A.13.2.1, A.18.1.4, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CM-7(a), CM-7(b), CM-6(a), MP-7, PR.AC-1, PR.AC-3, PR.AC-6, PR.AC-7, SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227, 1.1.9

Description

The autofs daemon mounts and unmounts filesystems, such as user home directories shared via NFS, on demand. In addition, autofs can be used to handle removable media, and the default configuration provides the cdrom device as /misc/cd. However, this method of providing access to removable media is not common, so autofs can almost always be disabled if NFS is not in use. Even if NFS is required, it may be possible to configure filesystem mounts statically by editing /etc/fstab rather than relying on the automounter.

The autofs service can be disabled with the following command:

$ sudo systemctl mask --now autofs.service

Rationale

Disabling the automounter permits the administrator to statically control filesystem mounting through /etc/fstab.

Additionally, automatically mounting filesystems permits easy introduction of unknown devices, thereby facilitating malicious activity.

Disable Mounting of cramfsxccdf_org.ssgproject.content_rule_kernel_module_cramfs_disabled low

Disable Mounting of cramfs

Rule IDxccdf_org.ssgproject.content_rule_kernel_module_cramfs_disabled
Result
pass
Time2024-04-05T12:59:12
Severitylow
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 3.4.6, CCI-000381, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, SRG-OS-000095-GPOS-00049, 1.1.1.1

Description

To configure the system to prevent the cramfs kernel module from being loaded, add the following line to the file /etc/modprobe.d/cramfs.conf:

install cramfs /bin/true
This effectively prevents usage of this uncommon filesystem. The cramfs filesystem type is a compressed read-only Linux filesystem embedded in small footprint systems. A cramfs image can be used without having to first decompress the image.

Rationale

Removing support for unneeded filesystem types reduces the local attack surface of the server.

Disable Modprobe Loading of USB Storage Driverxccdf_org.ssgproject.content_rule_kernel_module_usb-storage_disabled medium

Disable Modprobe Loading of USB Storage Driver

Rule IDxccdf_org.ssgproject.content_rule_kernel_module_usb-storage_disabled
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  1, 12, 15, 16, 5, APO13.01, DSS01.04, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.21, CCI-000366, CCI-000778, CCI-001958, 164.308(a)(3)(i), 164.308(a)(3)(ii)(A), 164.310(d)(1), 164.310(d)(2), 164.312(a)(1), 164.312(a)(2)(iv), 164.312(b), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, SR 1.1, SR 1.10, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.6, A.11.2.6, A.13.1.1, A.13.2.1, A.18.1.4, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3, CM-7(a), CM-7(b), CM-6(a), MP-7, PR.AC-1, PR.AC-3, PR.AC-6, PR.AC-7, SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227, 1.1.10

Description

To prevent USB storage devices from being used, configure the kernel module loading system to prevent automatic loading of the USB storage driver. To configure the system to prevent the usb-storage kernel module from being loaded, add the following line to the file /etc/modprobe.d/usb-storage.conf:

install usb-storage /bin/true
This will prevent the modprobe program from loading the usb-storage module, but will not prevent an administrator (or another program) from using the insmod program to load the module manually.

Rationale

USB storage devices such as thumb drives can be used to introduce malicious software.

Add nodev Option to /dev/shmxccdf_org.ssgproject.content_rule_mount_option_dev_shm_nodev medium

Add nodev Option to /dev/shm

Rule IDxccdf_org.ssgproject.content_rule_mount_option_dev_shm_nodev
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-001764, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.8.1

Description

The nodev mount option can be used to prevent creation of device files in /dev/shm. Legitimate character and block devices should not exist within temporary directories like /dev/shm. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /dev/shm.

Rationale

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Add nosuid Option to /dev/shmxccdf_org.ssgproject.content_rule_mount_option_dev_shm_nosuid medium

Add nosuid Option to /dev/shm

Rule IDxccdf_org.ssgproject.content_rule_mount_option_dev_shm_nosuid
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-001764, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.8.3

Description

The nosuid mount option can be used to prevent execution of setuid programs in /dev/shm. The SUID and SGID permissions should not be required in these world-writable directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /dev/shm.

Rationale

The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from temporary storage partitions.

Add nodev Option to /homexccdf_org.ssgproject.content_rule_mount_option_home_nodev unknown

Add nodev Option to /home

Rule IDxccdf_org.ssgproject.content_rule_mount_option_home_nodev
Result
notapplicable
Time2024-04-05T12:59:12
Severityunknown
Identifiers and References

References:  BP28(R12), SRG-OS-000368-GPOS-00154, 1.1.7.2

Description

The nodev mount option can be used to prevent device files from being created in /home. Legitimate character and block devices should exist only in the /dev directory on the root partition or within chroot jails built for system services. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /home.

Rationale

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Add nosuid Option to /homexccdf_org.ssgproject.content_rule_mount_option_home_nosuid medium

Add nosuid Option to /home

Rule IDxccdf_org.ssgproject.content_rule_mount_option_home_nosuid
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R12), 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, SRG-OS-000480-GPOS-00227, 1.1.7.3

Description

The nosuid mount option can be used to prevent execution of setuid programs in /home. The SUID and SGID permissions should not be required in these user data directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /home.

Rationale

The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from user home directory partitions.

Add nodev Option to /tmpxccdf_org.ssgproject.content_rule_mount_option_tmp_nodev medium

Add nodev Option to /tmp

Rule IDxccdf_org.ssgproject.content_rule_mount_option_tmp_nodev
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R12), 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-001764, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.2.2

Description

The nodev mount option can be used to prevent device files from being created in /tmp. Legitimate character and block devices should not exist within temporary directories like /tmp. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /tmp.

Rationale

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Add noexec Option to /tmpxccdf_org.ssgproject.content_rule_mount_option_tmp_noexec medium

Add noexec Option to /tmp

Rule IDxccdf_org.ssgproject.content_rule_mount_option_tmp_noexec
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R12), 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-001764, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.2.3

Description

The noexec mount option can be used to prevent binaries from being executed out of /tmp. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /tmp.

Rationale

Allowing users to execute binaries from world-writable directories such as /tmp should never be necessary in normal operation and can expose the system to potential compromise.

Add nosuid Option to /tmpxccdf_org.ssgproject.content_rule_mount_option_tmp_nosuid medium

Add nosuid Option to /tmp

Rule IDxccdf_org.ssgproject.content_rule_mount_option_tmp_nosuid
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R12), 11, 13, 14, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06, CCI-001764, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.2.4

Description

The nosuid mount option can be used to prevent execution of setuid programs in /tmp. The SUID and SGID permissions should not be required in these world-writable directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /tmp.

Rationale

The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from temporary storage partitions.

Add nodev Option to /var/log/auditxccdf_org.ssgproject.content_rule_mount_option_var_log_audit_nodev medium

Add nodev Option to /var/log/audit

Rule IDxccdf_org.ssgproject.content_rule_mount_option_var_log_audit_nodev
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-001764, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.6.3

Description

The nodev mount option can be used to prevent device files from being created in /var/log/audit. Legitimate character and block devices should exist only in the /dev directory on the root partition or within chroot jails built for system services. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /var/log/audit.

Rationale

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Add noexec Option to /var/log/auditxccdf_org.ssgproject.content_rule_mount_option_var_log_audit_noexec medium

Add noexec Option to /var/log/audit

Rule IDxccdf_org.ssgproject.content_rule_mount_option_var_log_audit_noexec
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-001764, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.6.2

Description

The noexec mount option can be used to prevent binaries from being executed out of /var/log/audit. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /var/log/audit.

Rationale

Allowing users to execute binaries from directories containing audit log files such as /var/log/audit should never be necessary in normal operation and can expose the system to potential compromise.

Add nosuid Option to /var/log/auditxccdf_org.ssgproject.content_rule_mount_option_var_log_audit_nosuid medium

Add nosuid Option to /var/log/audit

Rule IDxccdf_org.ssgproject.content_rule_mount_option_var_log_audit_nosuid
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-001764, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.6.4

Description

The nosuid mount option can be used to prevent execution of setuid programs in /var/log/audit. The SUID and SGID permissions should not be required in directories containing audit log files. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /var/log/audit.

Rationale

The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from partitions designated for audit log files.

Add nodev Option to /var/logxccdf_org.ssgproject.content_rule_mount_option_var_log_nodev medium

Add nodev Option to /var/log

Rule IDxccdf_org.ssgproject.content_rule_mount_option_var_log_nodev
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CCI-001764, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.5.2

Description

The nodev mount option can be used to prevent device files from being created in /var/log. Legitimate character and block devices should exist only in the /dev directory on the root partition or within chroot jails built for system services. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /var/log.

Rationale

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Add noexec Option to /var/logxccdf_org.ssgproject.content_rule_mount_option_var_log_noexec medium

Add noexec Option to /var/log

Rule IDxccdf_org.ssgproject.content_rule_mount_option_var_log_noexec
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R12), CCI-001764, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.5.3

Description

The noexec mount option can be used to prevent binaries from being executed out of /var/log. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /var/log.

Rationale

Allowing users to execute binaries from directories containing log files such as /var/log should never be necessary in normal operation and can expose the system to potential compromise.

Add nosuid Option to /var/logxccdf_org.ssgproject.content_rule_mount_option_var_log_nosuid medium

Add nosuid Option to /var/log

Rule IDxccdf_org.ssgproject.content_rule_mount_option_var_log_nosuid
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R12), CCI-001764, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.5.4

Description

The nosuid mount option can be used to prevent execution of setuid programs in /var/log. The SUID and SGID permissions should not be required in directories containing log files. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /var/log.

Rationale

The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from partitions designated for log files.

Add nodev Option to /varxccdf_org.ssgproject.content_rule_mount_option_var_nodev medium

Add nodev Option to /var

Rule IDxccdf_org.ssgproject.content_rule_mount_option_var_nodev
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7, PR.IP-1, PR.PT-2, PR.PT-3, SRG-OS-000368-GPOS-00154, 1.1.3.2

Description

The nodev mount option can be used to prevent device files from being created in /var. Legitimate character and block devices should exist only in the /dev directory on the root partition or within chroot jails built for system services. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /var.

Rationale

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Add nosuid Option to /varxccdf_org.ssgproject.content_rule_mount_option_var_nosuid medium

Add nosuid Option to /var

Rule IDxccdf_org.ssgproject.content_rule_mount_option_var_nosuid
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R12), 1.1.3.3

Description

The nosuid mount option can be used to prevent execution of setuid programs in /var. The SUID and SGID permissions should not be required for this directory. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /var.

Rationale

The presence of SUID and SGID executables should be tightly controlled.

Add nodev Option to /var/tmpxccdf_org.ssgproject.content_rule_mount_option_var_tmp_nodev medium

Add nodev Option to /var/tmp

Rule IDxccdf_org.ssgproject.content_rule_mount_option_var_tmp_nodev
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R12), CCI-001764, SRG-OS-000368-GPOS-00154, 1.1.4.4

Description

The nodev mount option can be used to prevent device files from being created in /var/tmp. Legitimate character and block devices should not exist within temporary directories like /var/tmp. Add the nodev option to the fourth column of /etc/fstab for the line which controls mounting of /var/tmp.

Rationale

The only legitimate location for device files is the /dev directory located on the root partition. The only exception to this is chroot jails.

Add noexec Option to /var/tmpxccdf_org.ssgproject.content_rule_mount_option_var_tmp_noexec medium

Add noexec Option to /var/tmp

Rule IDxccdf_org.ssgproject.content_rule_mount_option_var_tmp_noexec
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R12), CCI-001764, SRG-OS-000368-GPOS-00154, 1.1.4.2

Description

The noexec mount option can be used to prevent binaries from being executed out of /var/tmp. Add the noexec option to the fourth column of /etc/fstab for the line which controls mounting of /var/tmp.

Rationale

Allowing users to execute binaries from world-writable directories such as /var/tmp should never be necessary in normal operation and can expose the system to potential compromise.

Add nosuid Option to /var/tmpxccdf_org.ssgproject.content_rule_mount_option_var_tmp_nosuid medium

Add nosuid Option to /var/tmp

Rule IDxccdf_org.ssgproject.content_rule_mount_option_var_tmp_nosuid
Result
notapplicable
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R12), CCI-001764, SRG-OS-000368-GPOS-00154, 1.1.4.3

Description

The nosuid mount option can be used to prevent execution of setuid programs in /var/tmp. The SUID and SGID permissions should not be required in these world-writable directories. Add the nosuid option to the fourth column of /etc/fstab for the line which controls mounting of /var/tmp.

Rationale

The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from temporary storage partitions.

Disable Core Dumps for All Usersxccdf_org.ssgproject.content_rule_disable_users_coredumps medium

Disable Core Dumps for All Users

Rule IDxccdf_org.ssgproject.content_rule_disable_users_coredumps
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  1, 12, 13, 15, 16, 2, 7, 8, APO13.01, BAI04.04, DSS01.03, DSS03.05, DSS05.07, CCI-000366, SR 6.2, SR 7.1, SR 7.2, A.12.1.3, A.17.2.1, CM-6, SC-7(10), DE.CM-1, PR.DS-4, SRG-OS-000480-GPOS-00227, 1.5.4

Description

To disable core dumps for all users, add the following line to /etc/security/limits.conf, or to a file within the /etc/security/limits.d/ directory:

*     hard   core    0

Rationale

A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems.

Enable Randomized Layout of Virtual Address Spacexccdf_org.ssgproject.content_rule_sysctl_kernel_randomize_va_space medium

Enable Randomized Layout of Virtual Address Space

Rule IDxccdf_org.ssgproject.content_rule_sysctl_kernel_randomize_va_space
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  BP28(R23), 3.1.7, CCI-000366, CCI-002824, 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e), CIP-002-5 R1.1, CIP-002-5 R1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 4.1, CIP-004-6 4.2, CIP-004-6 R2.2.3, CIP-004-6 R2.2.4, CIP-004-6 R2.3, CIP-004-6 R4, CIP-005-6 R1, CIP-005-6 R1.1, CIP-005-6 R1.2, CIP-007-3 R3, CIP-007-3 R3.1, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, CIP-007-3 R8.4, CIP-009-6 R.1.1, CIP-009-6 R4, SC-30, SC-30(2), CM-6(a), Req-2.2.1, SRG-OS-000433-GPOS-00193, SRG-OS-000480-GPOS-00227, 1.5.1

Description

To set the runtime status of the kernel.randomize_va_space kernel parameter, run the following command:

$ sudo sysctl -w kernel.randomize_va_space=2
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:
kernel.randomize_va_space = 2

Rationale

Address space layout randomization (ASLR) makes it more difficult for an attacker to predict the location of attack code they have introduced into a process's address space during an attempt at exploitation. Additionally, ASLR makes it more difficult for an attacker to know the location of existing code in order to re-purpose it using return oriented programming (ROP) techniques.

Disable Apport Servicexccdf_org.ssgproject.content_rule_service_apport_disabled unknown

Disable Apport Service

Rule IDxccdf_org.ssgproject.content_rule_service_apport_disabled
Result
pass
Time2024-04-05T12:59:12
Severityunknown
Identifiers and References

References:  1.5.3

Description

The Apport modifies certain kernel configuration values at runtime which may decrease the overall security of the system and expose sensitive data. The apport service can be disabled with the following command:

$ sudo systemctl mask --now apport.service

Rationale

The Apport service modifies the kernel fs.suid_dumpable configuration at runtime which prevents other hardening from being persistent. Disabling the service prevents this behavior.

Uninstall avahi Server Packagexccdf_org.ssgproject.content_rule_package_avahi_removed medium

Uninstall avahi Server Package

Rule IDxccdf_org.ssgproject.content_rule_package_avahi_removed
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.2

Description

If the system does not need to have an Avahi server which implements the DNS Service Discovery and Multicast DNS protocols, the avahi-autoipd and avahi packages can be uninstalled.

Rationale

Automatic discovery of network services is not normally required for system functionality. It is recommended to remove this package to reduce the potential attack surface.

Disable Avahi Server Softwarexccdf_org.ssgproject.content_rule_service_avahi-daemon_disabled medium

Disable Avahi Server Software

Rule IDxccdf_org.ssgproject.content_rule_service_avahi-daemon_disabled
Result
pass
Time2024-04-05T12:59:12
Severitymedium
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.2

Description

The avahi-daemon service can be disabled with the following command:

$ sudo systemctl mask --now avahi-daemon.service

Rationale

Because the Avahi daemon service keeps an open network port, it is subject to network attacks. Its functionality is convenient but is only appropriate if the local network can be trusted.

Ensure that /etc/at.deny does not existxccdf_org.ssgproject.content_rule_file_at_deny_not_exist medium

Ensure that /etc/at.deny does not exist

Rule IDxccdf_org.ssgproject.content_rule_file_at_deny_not_exist
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  5.1.9

Description

The file /etc/at.deny should not exist. Use /etc/at.allow instead.

Rationale

Access to at should be restricted. It is easier to manage an allow list than a deny list.

Ensure that /etc/cron.deny does not existxccdf_org.ssgproject.content_rule_file_cron_deny_not_exist medium

Ensure that /etc/cron.deny does not exist

Rule IDxccdf_org.ssgproject.content_rule_file_cron_deny_not_exist
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  5.1.8

Description

The file /etc/cron.deny should not exist. Use /etc/cron.allow instead.

Rationale

Access to cron should be restricted. It is easier to manage an allow list than a deny list.

Verify Group Who Owns /etc/at.allow filexccdf_org.ssgproject.content_rule_file_groupowner_at_allow medium

Verify Group Who Owns /etc/at.allow file

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_at_allow
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  5.1.9

Description

If /etc/at.allow exists, it must be group-owned by root. To properly set the group owner of /etc/at.allow, run the command:

$ sudo chgrp root /etc/at.allow

Rationale

If the owner of the at.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.

Verify Group Who Owns /etc/cron.allow filexccdf_org.ssgproject.content_rule_file_groupowner_cron_allow medium

Verify Group Who Owns /etc/cron.allow file

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_cron_allow
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-000366, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.8

Description

If /etc/cron.allow exists, it must be group-owned by root. To properly set the group owner of /etc/cron.allow, run the command:

$ sudo chgrp root /etc/cron.allow

Rationale

If the owner of the cron.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.

Verify User Who Owns /etc/at.allow filexccdf_org.ssgproject.content_rule_file_owner_at_allow medium

Verify User Who Owns /etc/at.allow file

Rule IDxccdf_org.ssgproject.content_rule_file_owner_at_allow
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  5.1.9

Description

If /etc/at.allow exists, it must be owned by root. To properly set the owner of /etc/at.allow, run the command:

$ sudo chown root /etc/at.allow 

Rationale

If the owner of the at.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.

Verify User Who Owns /etc/cron.allow filexccdf_org.ssgproject.content_rule_file_owner_cron_allow medium

Verify User Who Owns /etc/cron.allow file

Rule IDxccdf_org.ssgproject.content_rule_file_owner_cron_allow
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, CCI-000366, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.8

Description

If /etc/cron.allow exists, it must be owned by root. To properly set the owner of /etc/cron.allow, run the command:

$ sudo chown root /etc/cron.allow 

Rationale

If the owner of the cron.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.

Verify Permissions on /etc/at.allow filexccdf_org.ssgproject.content_rule_file_permissions_at_allow medium

Verify Permissions on /etc/at.allow file

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_at_allow
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  5.1.9

Description

If /etc/at.allow exists, it must have permissions 0640 or more restrictive. To properly set the permissions of /etc/at.allow, run the command:

$ sudo chmod 0640 /etc/at.allow

Rationale

If the permissions of the at.allow file are not set to 0640 or more restrictive, the possibility exists for an unauthorized user to view or edit sensitive information.

Verify Permissions on /etc/cron.allow filexccdf_org.ssgproject.content_rule_file_permissions_cron_allow medium

Verify Permissions on /etc/cron.allow file

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_cron_allow
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  SRG-OS-000480-GPOS-00227, 5.1.8

Description

If /etc/cron.allow exists, it must have permissions 0640 or more restrictive. To properly set the permissions of /etc/cron.allow, run the command:

$ sudo chmod 0640 /etc/cron.allow

Rationale

If the permissions of the cron.allow file are not set to 0640 or more restrictive, the possibility exists for an unauthorized user to view or edit sensitive information.

Enable cron Servicexccdf_org.ssgproject.content_rule_service_cron_enabled medium

Enable cron Service

Rule IDxccdf_org.ssgproject.content_rule_service_cron_enabled
Result
unknown
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-6(a), PR.IP-1, PR.PT-3, 5.1.1

Description

The crond service is used to execute commands at preconfigured times. It is required by almost all systems to perform necessary maintenance tasks, such as notifying root of system activity. The cron service can be enabled with the following command:

$ sudo systemctl enable cron.service

Rationale

Due to its usage for maintenance and security-supporting tasks, enabling the cron daemon is essential.

Remediation Puppet snippet:   (show)

Complexity:low
Disruption:low
Strategy:enable
include enable_cron

class enable_cron {
  service {'cron':
    enable => true,
    ensure => 'running',
  }
}
Remediation Ansible snippet:   (show)

Complexity:low
Disruption:low
Strategy:enable
- name: Enable service cron
  block:

  - name: Gather the package facts
    package_facts:
      manager: auto

  - name: Enable service cron
    service:
      name: cron
      enabled: 'yes'
      state: started
      masked: 'no'
    when:
    - '"cron" in ansible_facts.packages'
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-53-CM-6(a)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_cron_enabled
Remediation Shell script:   (show)

Complexity:low
Disruption:low
Strategy:enable
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

SYSTEMCTL_EXEC='/usr/bin/systemctl'
"$SYSTEMCTL_EXEC" unmask 'cron.service'
"$SYSTEMCTL_EXEC" start 'cron.service'
"$SYSTEMCTL_EXEC" enable 'cron.service'

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
Remediation script:   (show)


[customizations.services]
enabled = ["cron"]
Verify Group Who Owns cron.dxccdf_org.ssgproject.content_rule_file_groupowner_cron_d medium

Verify Group Who Owns cron.d

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_cron_d
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.7

Description

To properly set the group owner of /etc/cron.d, run the command:

$ sudo chgrp root /etc/cron.d

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.

Verify Group Who Owns cron.dailyxccdf_org.ssgproject.content_rule_file_groupowner_cron_daily medium

Verify Group Who Owns cron.daily

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_cron_daily
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.4

Description

To properly set the group owner of /etc/cron.daily, run the command:

$ sudo chgrp root /etc/cron.daily

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.

Verify Group Who Owns cron.hourlyxccdf_org.ssgproject.content_rule_file_groupowner_cron_hourly medium

Verify Group Who Owns cron.hourly

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_cron_hourly
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.3

Description

To properly set the group owner of /etc/cron.hourly, run the command:

$ sudo chgrp root /etc/cron.hourly

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.

Verify Group Who Owns cron.monthlyxccdf_org.ssgproject.content_rule_file_groupowner_cron_monthly medium

Verify Group Who Owns cron.monthly

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_cron_monthly
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.6

Description

To properly set the group owner of /etc/cron.monthly, run the command:

$ sudo chgrp root /etc/cron.monthly

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.

Verify Group Who Owns cron.weeklyxccdf_org.ssgproject.content_rule_file_groupowner_cron_weekly medium

Verify Group Who Owns cron.weekly

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_cron_weekly
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.5

Description

To properly set the group owner of /etc/cron.weekly, run the command:

$ sudo chgrp root /etc/cron.weekly

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.

Verify Group Who Owns Crontabxccdf_org.ssgproject.content_rule_file_groupowner_crontab medium

Verify Group Who Owns Crontab

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_crontab
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.2

Description

To properly set the group owner of /etc/crontab, run the command:

$ sudo chgrp root /etc/crontab

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.

Verify Owner on cron.dxccdf_org.ssgproject.content_rule_file_owner_cron_d medium

Verify Owner on cron.d

Rule IDxccdf_org.ssgproject.content_rule_file_owner_cron_d
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.7

Description

To properly set the owner of /etc/cron.d, run the command:

$ sudo chown root /etc/cron.d 

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.

Verify Owner on cron.dailyxccdf_org.ssgproject.content_rule_file_owner_cron_daily medium

Verify Owner on cron.daily

Rule IDxccdf_org.ssgproject.content_rule_file_owner_cron_daily
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.4

Description

To properly set the owner of /etc/cron.daily, run the command:

$ sudo chown root /etc/cron.daily 

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.

Verify Owner on cron.hourlyxccdf_org.ssgproject.content_rule_file_owner_cron_hourly medium

Verify Owner on cron.hourly

Rule IDxccdf_org.ssgproject.content_rule_file_owner_cron_hourly
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.3

Description

To properly set the owner of /etc/cron.hourly, run the command:

$ sudo chown root /etc/cron.hourly 

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.

Verify Owner on cron.monthlyxccdf_org.ssgproject.content_rule_file_owner_cron_monthly medium

Verify Owner on cron.monthly

Rule IDxccdf_org.ssgproject.content_rule_file_owner_cron_monthly
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.6

Description

To properly set the owner of /etc/cron.monthly, run the command:

$ sudo chown root /etc/cron.monthly 

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.

Verify Owner on cron.weeklyxccdf_org.ssgproject.content_rule_file_owner_cron_weekly medium

Verify Owner on cron.weekly

Rule IDxccdf_org.ssgproject.content_rule_file_owner_cron_weekly
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.5

Description

To properly set the owner of /etc/cron.weekly, run the command:

$ sudo chown root /etc/cron.weekly 

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.

Verify Owner on crontabxccdf_org.ssgproject.content_rule_file_owner_crontab medium

Verify Owner on crontab

Rule IDxccdf_org.ssgproject.content_rule_file_owner_crontab
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.2

Description

To properly set the owner of /etc/crontab, run the command:

$ sudo chown root /etc/crontab 

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.

Verify Permissions on cron.dxccdf_org.ssgproject.content_rule_file_permissions_cron_d medium

Verify Permissions on cron.d

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_cron_d
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.7

Description

To properly set the permissions of /etc/cron.d, run the command:

$ sudo chmod 0700 /etc/cron.d

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.

Verify Permissions on cron.dailyxccdf_org.ssgproject.content_rule_file_permissions_cron_daily medium

Verify Permissions on cron.daily

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_cron_daily
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.4

Description

To properly set the permissions of /etc/cron.daily, run the command:

$ sudo chmod 0700 /etc/cron.daily

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.

Verify Permissions on cron.hourlyxccdf_org.ssgproject.content_rule_file_permissions_cron_hourly medium

Verify Permissions on cron.hourly

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_cron_hourly
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.3

Description

To properly set the permissions of /etc/cron.hourly, run the command:

$ sudo chmod 0700 /etc/cron.hourly

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.

Verify Permissions on cron.monthlyxccdf_org.ssgproject.content_rule_file_permissions_cron_monthly medium

Verify Permissions on cron.monthly

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_cron_monthly
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.6

Description

To properly set the permissions of /etc/cron.monthly, run the command:

$ sudo chmod 0700 /etc/cron.monthly

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.

Verify Permissions on cron.weeklyxccdf_org.ssgproject.content_rule_file_permissions_cron_weekly medium

Verify Permissions on cron.weekly

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_cron_weekly
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.5

Description

To properly set the permissions of /etc/cron.weekly, run the command:

$ sudo chmod 0700 /etc/cron.weekly

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.

Verify Permissions on crontabxccdf_org.ssgproject.content_rule_file_permissions_crontab medium

Verify Permissions on crontab

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_crontab
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.1.2

Description

To properly set the permissions of /etc/crontab, run the command:

$ sudo chmod 0600 /etc/crontab

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.

Uninstall the nis packagexccdf_org.ssgproject.content_rule_package_nis_removed low

Uninstall the nis package

Rule IDxccdf_org.ssgproject.content_rule_package_nis_removed
Result
pass
Time2024-04-05T12:59:22
Severitylow
Identifiers and References

References:  2.2.14

Description

The support for Yellowpages should not be installed unless it is required.

Rationale

NIS is the historical SUN service for central account management, more and more replaced by LDAP. NIS does not support efficiently security constraints, ACL, etc. and should not be used.

Uninstall DHCP Server Packagexccdf_org.ssgproject.content_rule_package_dhcp_removed medium

Uninstall DHCP Server Package

Rule IDxccdf_org.ssgproject.content_rule_package_dhcp_removed
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  BP28(R1), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.4

Description

If the system does not need to act as a DHCP server, the dhcp package can be uninstalled. The isc-dhcp-server package can be removed with the following command:

$ apt-get remove isc-dhcp-server

Rationale

Removing the DHCP server ensures that it cannot be easily or accidentally reactivated and disrupt network operation.

Uninstall bind Packagexccdf_org.ssgproject.content_rule_package_bind_removed low

Uninstall bind Package

Rule IDxccdf_org.ssgproject.content_rule_package_bind_removed
Result
pass
Time2024-04-05T12:59:22
Severitylow
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.7

Description

The named service is provided by the bind package. The bind package can be removed with the following command:

$ apt-get remove bind

Rationale

If there is no need to make DNS server software available, removing it provides a safeguard against its activation.

Uninstall vsftpd Packagexccdf_org.ssgproject.content_rule_package_vsftpd_removed high

Uninstall vsftpd Package

Rule IDxccdf_org.ssgproject.content_rule_package_vsftpd_removed
Result
pass
Time2024-04-05T12:59:22
Severityhigh
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000197, CCI-000366, CCI-000381, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), IA-5(1)(c), IA-5(1).1(v), CM-7, CM-7.1(ii), PR.IP-1, PR.PT-3, Req-2.2.4, SRG-OS-000074-GPOS-00042, SRG-OS-000095-GPOS-00049, SRG-OS-000480-GPOS-00227, 2.2.8

Description

The vsftpd package can be removed with the following command:

 $ apt-get remove vsftpd

Rationale

Removing the vsftpd package decreases the risk of its accidental activation.

Uninstall httpd Packagexccdf_org.ssgproject.content_rule_package_httpd_removed unknown

Uninstall httpd Package

Rule IDxccdf_org.ssgproject.content_rule_package_httpd_removed
Result
pass
Time2024-04-05T12:59:22
Severityunknown
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.9

Description

The apache2 package can be removed with the following command:

$ apt-get remove apache2

Rationale

If there is no need to make the web server software available, removing it provides a safeguard against its activation.

Uninstall nginx Packagexccdf_org.ssgproject.content_rule_package_nginx_removed unknown

Uninstall nginx Package

Rule IDxccdf_org.ssgproject.content_rule_package_nginx_removed
Result
pass
Time2024-04-05T12:59:22
Severityunknown
Identifiers and References

References:  BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.9

Description

The nginx package can be removed with the following command:

$ apt-get remove nginx

Rationale

If there is no need to make the web server software available, removing it provides a safeguard against its activation.

Uninstall cyrus-imapd Packagexccdf_org.ssgproject.content_rule_package_cyrus-imapd_removed unknown

Uninstall cyrus-imapd Package

Rule IDxccdf_org.ssgproject.content_rule_package_cyrus-imapd_removed
Result
pass
Time2024-04-05T12:59:22
Severityunknown
Identifiers and References

References:  2.2.10

Description

The cyrus-imapd package can be removed with the following command:

$ apt-get remove cyrus-imapd

Rationale

If there is no need to make the cyrus-imapd software available, removing it provides a safeguard against its activation.

Uninstall dovecot Packagexccdf_org.ssgproject.content_rule_package_dovecot_removed unknown

Uninstall dovecot Package

Rule IDxccdf_org.ssgproject.content_rule_package_dovecot_removed
Result
pass
Time2024-04-05T12:59:22
Severityunknown
Identifiers and References

References:  2.2.10

Description

The dovecot-core package can be removed with the following command:

$ apt-get remove dovecot-core

Rationale

If there is no need to make the Dovecot software available, removing it provides a safeguard against its activation.

Ensure LDAP client is not installedxccdf_org.ssgproject.content_rule_package_openldap-clients_removed low

Ensure LDAP client is not installed

Rule IDxccdf_org.ssgproject.content_rule_package_openldap-clients_removed
Result
pass
Time2024-04-05T12:59:22
Severitylow
Identifiers and References

References:  Req-2.2.4, 2.3.5

Description

The Lightweight Directory Access Protocol (LDAP) is a service that provides a method for looking up information from a central database. The lapd-utils package can be removed with the following command:

$ apt-get remove lapd-utils

Rationale

If the system does not need to act as an LDAP client, it is recommended that the software is removed to reduce the potential attack surface.

Uninstall openldap-servers Packagexccdf_org.ssgproject.content_rule_package_openldap-servers_removed low

Uninstall openldap-servers Package

Rule IDxccdf_org.ssgproject.content_rule_package_openldap-servers_removed
Result
pass
Time2024-04-05T12:59:22
Severitylow
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000366, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.5

Description

The slapd package is not installed by default on a Ubuntu 22.04 system. It is needed only by the OpenLDAP server, not by the clients which use LDAP for authentication. If the system is not intended for use as an LDAP Server it should be removed.

Rationale

Unnecessary packages should not be installed to decrease the attack surface of the system. While this software is clearly essential on an LDAP server, it is not necessary on typical desktop or workstation systems.

Disable Postfix Network Listeningxccdf_org.ssgproject.content_rule_postfix_network_listening_disabled medium

Disable Postfix Network Listening

Rule IDxccdf_org.ssgproject.content_rule_postfix_network_listening_disabled
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  BP28(R48), 11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, CCI-000382, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, Req-2.2.4, 2.2.15

Description

Edit the file /etc/postfix/main.cf to ensure that only the following inet_interfaces line appears:

inet_interfaces = loopback-only

Rationale

This ensures postfix accepts mail messages (such as cron job reports) from the local system only, and not from the network, which protects it from network attack.

Ensure Mail Transfer Agent is not Listening on any non-loopback Addressxccdf_org.ssgproject.content_rule_has_nonlocal_mta medium

Ensure Mail Transfer Agent is not Listening on any non-loopback Address

Rule IDxccdf_org.ssgproject.content_rule_has_nonlocal_mta
Result
pass
Time2024-04-05T12:59:22
Severitymedium
Identifiers and References

References:  2.2.15

Description

Mail Transfer Agents (MTA), such as sendmail and Postfix, are used to listen for incoming mail and transfer the messages to the appropriate user or mail server. If the system is not intended to be a mail server, it is recommended that the MTA be configured to only process local mail.

Rationale

The software for all Mail Transfer Agents is complex and most have a long history of security issues. While it is important to ensure that the system can process local mail messages, it is not necessary to have the MTA's daemon listening on a port unless the server is intended to be a mail server that receives and processes mail from other systems.

Uninstall rpcbind Packagexccdf_org.ssgproject.content_rule_package_rpcbind_removed low

Uninstall rpcbind Package

Rule IDxccdf_org.ssgproject.content_rule_package_rpcbind_removed
Result
pass
Time2024-04-05T12:59:33
Severitylow
Identifiers and References

References:  2.3.6

Description

The rpcbind utility maps RPC services to the ports on which they listen. RPC processes notify rpcbind when they start, registering the ports they are listening on and the RPC program numbers they expect to serve. The rpcbind service redirects the client to the proper port number so it can communicate with the requested service. If the system does not require RPC (such as for NFS servers) then this service should be disabled. The rpcbind package can be removed with the following command:

$ apt-get remove rpcbind

Rationale

If the system does not require rpc based services, it is recommended that rpcbind be disabled to reduce the attack surface.

Uninstall nfs-kernel-server Packagexccdf_org.ssgproject.content_rule_package_nfs-kernel-server_removed low

Uninstall nfs-kernel-server Package

Rule IDxccdf_org.ssgproject.content_rule_package_nfs-kernel-server_removed
Result
pass
Time2024-04-05T12:59:33
Severitylow
Identifiers and References

References:  2.2.6

Description

The nfs-kernel-server package can be removed with the following command:

$ apt-get remove nfs-kernel-server

Rationale

If the system does not export NFS shares or act as an NFS client, it is recommended that these services be removed to reduce the remote attack surface.

Install the systemd_timesyncd Servicexccdf_org.ssgproject.content_rule_package_timesyncd_installed high

Install the systemd_timesyncd Service

Rule IDxccdf_org.ssgproject.content_rule_package_timesyncd_installed
Result
pass
Time2024-04-05T12:59:33
Severityhigh
Identifiers and References

References:  NT012(R03), 1, 14, 15, 16, 3, 5, 6, APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01, CCI-000160, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, CM-6(a), PR.PT-1, Req-10.4, 2.1.1.1

Description

The systemd_timesyncd service should be installed.

Rationale

Time synchronization (using NTP) is required by almost all network and administrative tasks (syslog, cryptographic based services (authentication, etc.), etc.). systemd_timesyncd is a part of the systemd suite and acts as a NTP client.

The Chronyd service is enabledxccdf_org.ssgproject.content_rule_service_chronyd_enabled medium

The Chronyd service is enabled

Rule IDxccdf_org.ssgproject.content_rule_service_chronyd_enabled
Result
notapplicable
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  0988, 1405, SRG-OS-000355-GPOS-00143, 2.1.2.3

Description

chrony is a daemon which implements the Network Time Protocol (NTP) is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. More information on chrony can be found at http://chrony.tuxfamily.org/. Chrony can be configured to be a client and/or a server. To enable Chronyd service, you can run: # systemctl enable chronyd.service This recommendation only applies if chrony is in use on the system.

Rationale

If chrony is in use on the system proper configuration is vital to ensuring time synchronization is working properly.

Enable the NTP Daemonxccdf_org.ssgproject.content_rule_service_ntp_enabled high

Enable the NTP Daemon

Rule IDxccdf_org.ssgproject.content_rule_service_ntp_enabled
Result
notapplicable
Time2024-04-05T12:59:33
Severityhigh
Identifiers and References

References:  NT012(R03), 1, 14, 15, 16, 3, 5, 6, APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01, CCI-000160, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, CM-6(a), AU-8(1)(a), PR.PT-1, Req-10.4, 2.1.4.4

Description

The ntp service can be enabled with the following command:

$ sudo systemctl enable ntp.service

Rationale

Enabling the ntp service ensures that the ntp service will be running and that the system will synchronize its time to any servers specified. This is important whether the system is configured to be a client (and synchronize only its own clock) or it is also acting as an NTP server to other systems. Synchronizing time is essential for authentication services such as Kerberos, but it is also important for maintaining accurate logs and auditing possible security breaches.

The NTP daemon offers all of the functionality of ntpdate, which is now deprecated.

Ensure that chronyd is running under chrony user accountxccdf_org.ssgproject.content_rule_chronyd_run_as_chrony_user medium

Ensure that chronyd is running under chrony user account

Rule IDxccdf_org.ssgproject.content_rule_chronyd_run_as_chrony_user
Result
notapplicable
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  2.1.2.2

Description

chrony is a daemon which implements the Network Time Protocol (NTP). It is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. More information on chrony can be found at http://chrony.tuxfamily.org/. Chrony can be configured to be a client and/or a server. To ensure that chronyd is running under chrony user account, user variable in /etc/chrony/chrony.conf is set to _chrony or is absent:

user _chrony
This recommendation only applies if chrony is in use on the system.

Rationale

If chrony is in use on the system proper configuration is vital to ensuring time synchronization is working properly.

Configure server restrictions for ntpdxccdf_org.ssgproject.content_rule_ntpd_configure_restrictions medium

Configure server restrictions for ntpd

Rule IDxccdf_org.ssgproject.content_rule_ntpd_configure_restrictions
Result
notapplicable
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  2.1.4.1

Description

ntpd is a daemon which implements the Network Time Protocol (NTP). It is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. More information on NTP can be found at http://www.ntp.org. ntp can be configured to be a client and/or a server. To ensure that ntpd implements correct server restrictions, make sure that the following lines exist in the file /etc/ntpd.conf:

restrict -4 default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
This recommendation only applies if ntp is in use on the system.

Rationale

If ntp is in use on the system proper configuration is vital to ensuring time synchronization is working properly.

Configure ntpd To Run As ntp Userxccdf_org.ssgproject.content_rule_ntpd_run_as_ntp_user medium

Configure ntpd To Run As ntp User

Rule IDxccdf_org.ssgproject.content_rule_ntpd_run_as_ntp_user
Result
notapplicable
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  2.1.4.3

Description

ntp is a daemon which implements the Network Time Protocol (NTP). It is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. More information on NTP can be found at http://www.ntp.org. ntp can be configured to be a client and/or a server. To ensure that ntpd is running as ntp user, Add or edit the OPTIONS variable in /etc/sysconfig/ntpd to include ' -u ntp:ntp ':

OPTIONS="-u ntp:ntp"
This recommendation only applies if ntp is in use on the system.

Rationale

If ntp is in use on the system proper configuration is vital to ensuring time synchronization is working properly. Running ntpd under dedicated user accounts limits the attack surface for potential attacker exploiting security flaws in the daemon or the protocol.

Uninstall rsh Packagexccdf_org.ssgproject.content_rule_package_rsh_removed unknown

Uninstall rsh Package

Rule IDxccdf_org.ssgproject.content_rule_package_rsh_removed
Result
pass
Time2024-04-05T12:59:33
Severityunknown
Identifiers and References

References:  BP28(R1), 3.1.13, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), A.8.2.3, A.13.1.1, A.13.2.1, A.13.2.3, A.14.1.2, A.14.1.3, 2.3.2

Description

The rsh-client package contains the client commands for the rsh services

Rationale

These legacy clients contain numerous security exposures and have been replaced with the more secure SSH package. Even if the server is removed, it is best to ensure the clients are also removed to prevent users from inadvertently attempting to use these commands and therefore exposing their credentials. Note that removing the rsh-client package removes the clients for rsh,rcp, and rlogin.

Remove Rsh Trust Filesxccdf_org.ssgproject.content_rule_no_rsh_trust_files high

Remove Rsh Trust Files

Rule IDxccdf_org.ssgproject.content_rule_no_rsh_trust_files
Result
pass
Time2024-04-05T12:59:33
Severityhigh
Identifiers and References

References:  11, 12, 14, 15, 3, 8, 9, APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06, CCI-001436, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4, 6.2.16

Description

The files /etc/hosts.equiv and ~/.rhosts (in each user's home directory) list remote hosts and users that are trusted by the local system when using the rshd daemon. To remove these files, run the following command to delete them from any location:

$ sudo rm /etc/hosts.equiv
$ rm ~/.rhosts

Rationale

This action is only meaningful if .rhosts support is permitted through PAM. Trust files are convenient, but when used in conjunction with the R-services, they can allow unauthenticated access to a system.

Uninstall talk Packagexccdf_org.ssgproject.content_rule_package_talk_removed medium

Uninstall talk Package

Rule IDxccdf_org.ssgproject.content_rule_package_talk_removed
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  BP28(R1), 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 2.3.3

Description

The talk package contains the client program for the Internet talk protocol, which allows the user to chat with other users on different systems. Talk is a communication program which copies lines from one terminal to the terminal of another user. The talk package can be removed with the following command:

$ apt-get remove talk

Rationale

The talk software presents a security risk as it uses unencrypted protocols for communications. Removing the talk package decreases the risk of the accidental (or intentional) activation of talk client program.

Remove telnet Clientsxccdf_org.ssgproject.content_rule_package_telnet_removed low

Remove telnet Clients

Rule IDxccdf_org.ssgproject.content_rule_package_telnet_removed
Result
pass
Time2024-04-05T12:59:33
Severitylow
Identifiers and References

References:  BP28(R1), 3.1.13, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), A.8.2.3, A.13.1.1, A.13.2.1, A.13.2.3, A.14.1.2, A.14.1.3, 2.3.4

Description

The telnet client allows users to start connections to other systems via the telnet protocol.

Rationale

The telnet protocol is insecure and unencrypted. The use of an unencrypted transmission medium could allow an unauthorized user to steal credentials. The ssh package provides an encrypted session and stronger security and is included in Ubuntu 22.04.

Uninstall CUPS Packagexccdf_org.ssgproject.content_rule_package_cups_removed unknown

Uninstall CUPS Package

Rule IDxccdf_org.ssgproject.content_rule_package_cups_removed
Result
pass
Time2024-04-05T12:59:33
Severityunknown
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.3

Description

The cups package can be removed with the following command:

$ apt-get remove cups

Rationale

If the system does not need to print jobs or accept print jobs from other systems, it is recommended that CUPS be removed to reduce the potential attack surface.

Disable the CUPS Servicexccdf_org.ssgproject.content_rule_service_cups_disabled unknown

Disable the CUPS Service

Rule IDxccdf_org.ssgproject.content_rule_service_cups_disabled
Result
pass
Time2024-04-05T12:59:33
Severityunknown
Identifiers and References

References:  11, 14, 3, 9, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2, CM-7(a), CM-7(b), CM-6(a), PR.IP-1, PR.PT-3, 2.2.3

Description

The cups service can be disabled with the following command:

$ sudo systemctl mask --now cups.service

Rationale

Turn off unneeded services to reduce attack surface.

Uninstall squid Packagexccdf_org.ssgproject.content_rule_package_squid_removed unknown

Uninstall squid Package

Rule IDxccdf_org.ssgproject.content_rule_package_squid_removed
Result
pass
Time2024-04-05T12:59:33
Severityunknown
Identifiers and References

References:  2.2.12

Description

The squid package can be removed with the following command:

 $ apt-get remove squid

Rationale

If there is no need to make the proxy server software available, removing it provides a safeguard against its activation.

Uninstall Samba Packagexccdf_org.ssgproject.content_rule_package_samba_removed unknown

Uninstall Samba Package

Rule IDxccdf_org.ssgproject.content_rule_package_samba_removed
Result
pass
Time2024-04-05T12:59:33
Severityunknown
Identifiers and References

References:  2.2.11

Description

The samba package can be removed with the following command:

 $ apt-get remove samba

Rationale

If there is no need to make the Samba software available, removing it provides a safeguard against its activation.

Uninstall net-snmp Packagexccdf_org.ssgproject.content_rule_package_net-snmp_removed unknown

Uninstall net-snmp Package

Rule IDxccdf_org.ssgproject.content_rule_package_net-snmp_removed
Result
pass
Time2024-04-05T12:59:33
Severityunknown
Identifiers and References

References:  2.2.13

Description

The snmp package provides the snmpd service. The snmp package can be removed with the following command:

$ apt-get remove snmp

Rationale

If there is no need to run SNMP server software, removing the package provides a safeguard against its activation.

Set SSH Client Alive Count Maxxccdf_org.ssgproject.content_rule_sshd_set_keepalive medium

Set SSH Client Alive Count Max

Rule IDxccdf_org.ssgproject.content_rule_sshd_set_keepalive
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  BP28(R29), 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, 5.5.6, APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.11, CCI-000879, CCI-001133, CCI-002361, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2, Req-8.1.8, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109, 5.2.22

Description

The SSH server sends at most ClientAliveCountMax messages during a SSH session and waits for a response from the SSH client. The option ClientAliveInterval configures timeout after each ClientAliveCountMax message. If the SSH server does not receive a response from the client, then the connection is considered unresponsive and terminated. For SSH earlier than v8.2, a ClientAliveCountMax value of 0 causes a timeout precisely when the ClientAliveInterval is set. Starting with v8.2, a value of 0 disables the timeout functionality completely. If the option is set to a number greater than 0, then the session will be disconnected after ClientAliveInterval * ClientAliveCountMax seconds without receiving a keep alive message.

Rationale

This ensures a user login will be terminated as soon as the ClientAliveInterval is reached.

Set SSH Client Alive Intervalxccdf_org.ssgproject.content_rule_sshd_set_idle_timeout medium

Set SSH Client Alive Interval

Rule IDxccdf_org.ssgproject.content_rule_sshd_set_idle_timeout
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  BP28(R29), 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8, 5.5.6, APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10, 3.1.11, CCI-000879, CCI-001133, CCI-002361, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2, A.12.4.1, A.12.4.3, A.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5, CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CM-6(a), AC-17(a), AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a), DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2, Req-8.1.8, SRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109, SRG-OS-000395-GPOS-00175, 5.2.22

Description

SSH allows administrators to set a network responsiveness timeout interval. After this interval has passed, the unresponsive client will be automatically logged out.

To set this timeout interval, edit the following line in /etc/ssh/sshd_config as follows:

ClientAliveInterval 300


The timeout interval is given in seconds. For example, have a timeout of 10 minutes, set interval to 600.

If a shorter timeout has already been set for the login shell, that value will preempt any SSH setting made in /etc/ssh/sshd_config. Keep in mind that some processes may stop SSH from correctly detecting that the user is idle.

Rationale

Terminating an idle ssh session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been let unattended.

Warnings
warning  SSH disconnecting unresponsive clients will not have desired effect without also configuring ClientAliveCountMax in the SSH service configuration.
warning  Following conditions may prevent the SSH session to time out:
  • Remote processes on the remote machine generates output. As the output has to be transferred over the network to the client, the timeout is reset every time such transfer happens.
  • Any scp or sftp activity by the same user to the host resets the timeout.
Disable Host-Based Authenticationxccdf_org.ssgproject.content_rule_disable_host_auth medium

Disable Host-Based Authentication

Rule IDxccdf_org.ssgproject.content_rule_disable_host_auth
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  11, 12, 14, 15, 16, 18, 3, 5, 9, 5.5.6, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.1.12, CCI-000366, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, AC-3, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.IP-1, PR.PT-3, FIA_UAU.1, SRG-OS-000480-GPOS-00229, 5.2.8

Description

SSH's cryptographic host-based authentication is more secure than .rhosts authentication. However, it is not recommended that hosts unilaterally trust one another, even within an organization.
The default SSH configuration disables host-based authentication. The appropriate configuration is used if no value is set for HostbasedAuthentication.
To explicitly disable host-based authentication, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:

HostbasedAuthentication no

Rationale

SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.

Disable SSH Access via Empty Passwordsxccdf_org.ssgproject.content_rule_sshd_disable_empty_passwords high

Disable SSH Access via Empty Passwords

Rule IDxccdf_org.ssgproject.content_rule_sshd_disable_empty_passwords
Result
pass
Time2024-04-05T12:59:33
Severityhigh
Identifiers and References

References:  NT007(R17), 11, 12, 13, 14, 15, 16, 18, 3, 5, 9, 5.5.6, APO01.06, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, 3.1.1, 3.1.5, CCI-000366, CCI-000766, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, SR 7.6, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.DS-5, PR.IP-1, PR.PT-3, FIA_UAU.1, Req-2.2.6, SRG-OS-000106-GPOS-00053, SRG-OS-000480-GPOS-00229, SRG-OS-000480-GPOS-00227, 5.2.9

Description

Disallow SSH login with empty passwords. The default SSH configuration disables logins with empty passwords. The appropriate configuration is used if no value is set for PermitEmptyPasswords.
To explicitly disallow SSH login from accounts with empty passwords, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:

PermitEmptyPasswords no
Any accounts with empty passwords should be disabled immediately, and PAM configuration should prevent users from being able to assign themselves empty passwords.

Rationale

Configuring this setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere.

Disable SSH Support for .rhosts Filesxccdf_org.ssgproject.content_rule_sshd_disable_rhosts medium

Disable SSH Support for .rhosts Files

Rule IDxccdf_org.ssgproject.content_rule_sshd_disable_rhosts
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  11, 12, 14, 15, 16, 18, 3, 5, 9, 5.5.6, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06, 3.1.12, CCI-000366, 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.AC-4, PR.AC-6, PR.IP-1, PR.PT-3, FIA_UAU.1, SRG-OS-000480-GPOS-00227, 5.2.11

Description

SSH can emulate the behavior of the obsolete rsh command in allowing users to enable insecure access to their accounts via .rhosts files.
The default SSH configuration disables support for .rhosts. The appropriate configuration is used if no value is set for IgnoreRhosts.
To explicitly disable support for .rhosts files, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:

IgnoreRhosts yes

Rationale

SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.

Do Not Allow SSH Environment Optionsxccdf_org.ssgproject.content_rule_sshd_do_not_permit_user_env medium

Do Not Allow SSH Environment Options

Rule IDxccdf_org.ssgproject.content_rule_sshd_do_not_permit_user_env
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  11, 3, 9, 5.5.6, BAI10.01, BAI10.02, BAI10.03, BAI10.05, 3.1.12, CCI-000366, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.4.3.2, 4.3.4.3.3, SR 7.6, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, AC-17(a), CM-7(a), CM-7(b), CM-6(a), PR.IP-1, Req-2.2.6, SRG-OS-000480-GPOS-00229, 5.2.10

Description

Ensure that users are not able to override environment variables of the SSH daemon.
The default SSH configuration disables environment processing. The appropriate configuration is used if no value is set for PermitUserEnvironment.
To explicitly disable Environment options, add or correct the following /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:

PermitUserEnvironment no

Rationale

SSH environment options potentially allow users to bypass access restriction in some configurations.

Enable PAMxccdf_org.ssgproject.content_rule_sshd_enable_pam medium

Enable PAM

Rule IDxccdf_org.ssgproject.content_rule_sshd_enable_pam
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  CCI-000877, SRG-OS-000125-GPOS-00065, 5.2.6

Description

UsePAM Enables the Pluggable Authentication Module interface. If set to “yes” this will enable PAM authentication using ChallengeResponseAuthentication and PasswordAuthentication in addition to PAM account and session module processing for all authentication types. To enable PAM authentication, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:

UsePAM yes

Rationale

When UsePAM is set to yes, PAM runs through account and session types properly. This is important if you want to restrict access to services based off of IP, time or other factors of the account. Additionally, you can make sure users inherit certain environment variables on login or disallow access to the server.

Enable SSH Warning Bannerxccdf_org.ssgproject.content_rule_sshd_enable_warning_banner_net medium

Enable SSH Warning Banner

Rule IDxccdf_org.ssgproject.content_rule_sshd_enable_warning_banner_net
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  5.5.6, DSS05.04, DSS05.10, DSS06.10, 3.1.9, CCI-000048, CCI-000050, CCI-001384, CCI-001385, CCI-001386, CCI-001387, CCI-001388, 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii), 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9, A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3, AC-8(a), AC-8(c), AC-17(a), CM-6(a), PR.AC-7, FTA_TAB.1, SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088, 5.2.17

Description

To enable the warning banner and ensure it is consistent across the system, add or correct the following line in /etc/ssh/sshd_config:

Banner /etc/issue.net
Another section contains information on how to create an appropriate system-wide warning banner.

Rationale

The warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers. Alternatively, systems whose ownership should not be obvious should ensure usage of a banner that does not provide easy attribution.

Set LogLevel to INFOxccdf_org.ssgproject.content_rule_sshd_set_loglevel_info low

Set LogLevel to INFO

Rule IDxccdf_org.ssgproject.content_rule_sshd_set_loglevel_info
Result
pass
Time2024-04-05T12:59:33
Severitylow
Identifiers and References

References:  AC-17(a), CM-6(a), 5.2.5

Description

The INFO parameter specifices that record login and logout activity will be logged.
The default SSH configuration sets the log level to INFO. The appropriate configuration is used if no value is set for LogLevel.
To explicitly specify the log level in SSH, add or correct the following line in /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf:

LogLevel INFO

Rationale

SSH provides several logging levels with varying amounts of verbosity. DEBUG is specifically not recommended other than strictly for debugging SSH communications since it provides so much data that it is difficult to identify important security information. INFO level is the basic level that only records login activity of SSH users. In many situations, such as Incident Response, it is important to determine when a particular user was active on a system. The logout record can eliminate those users who disconnected, which helps narrow the field.

Set SSH authentication attempt limitxccdf_org.ssgproject.content_rule_sshd_set_max_auth_tries medium

Set SSH authentication attempt limit

Rule IDxccdf_org.ssgproject.content_rule_sshd_set_max_auth_tries
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561, 5.2.18

Description

The MaxAuthTries parameter specifies the maximum number of authentication attempts permitted per connection. Once the number of failures reaches half this value, additional failures are logged. to set MaxAUthTries edit /etc/ssh/sshd_config as follows:

MaxAuthTries 4

Rationale

Setting the MaxAuthTries parameter to a low number will minimize the risk of successful brute force attacks to the SSH server.

Set SSH MaxSessions limitxccdf_org.ssgproject.content_rule_sshd_set_max_sessions medium

Set SSH MaxSessions limit

Rule IDxccdf_org.ssgproject.content_rule_sshd_set_max_sessions
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  5.2.20

Description

The MaxSessions parameter specifies the maximum number of open sessions permitted from a given connection. To set MaxSessions edit /etc/ssh/sshd_config as follows:

MaxSessions 10

Rationale

To protect a system from denial of service due to a large number of concurrent sessions, use the rate limiting function of MaxSessions to protect availability of sshd logins and prevent overwhelming the daemon.

Ensure SSH MaxStartups is configuredxccdf_org.ssgproject.content_rule_sshd_set_maxstartups medium

Ensure SSH MaxStartups is configured

Rule IDxccdf_org.ssgproject.content_rule_sshd_set_maxstartups
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  5.2.19

Description

The MaxStartups parameter specifies the maximum number of concurrent unauthenticated connections to the SSH daemon. Additional connections will be dropped until authentication succeeds or the LoginGraceTime expires for a connection. To confgure MaxStartups, you should add or correct the following line in the /etc/ssh/sshd_config file:

MaxStartups 10:30:60
CIS recommends a MaxStartups value of '10:30:60', or more restrictive where dictated by site policy.

Rationale

To protect a system from denial of service due to a large number of pending authentication connection attempts, use the rate limiting function of MaxStartups to protect availability of sshd logins and prevent overwhelming the daemon.

Use Only Strong Ciphersxccdf_org.ssgproject.content_rule_sshd_use_strong_ciphers medium

Use Only Strong Ciphers

Rule IDxccdf_org.ssgproject.content_rule_sshd_use_strong_ciphers
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  5.2.13

Description

Limit the ciphers to strong algorithms. Counter (CTR) mode is also preferred over cipher-block chaining (CBC) mode. The following line in /etc/ssh/sshd_config demonstrates use of those ciphers:

Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
The man page sshd_config(5) contains a list of supported ciphers.

Rationale

Based on research conducted at various institutions, it was determined that the symmetric portion of the SSH Transport Protocol (as described in RFC 4253) has security weaknesses that allowed recovery of up to 32 bits of plaintext from a block of ciphertext that was encrypted with the Cipher Block Chaining (CBD) method. From that research, new Counter mode algorithms (as described in RFC4344) were designed that are not vulnerable to these types of attacks and these algorithms are now recommended for standard use.

Use Only Strong Key Exchange algorithmsxccdf_org.ssgproject.content_rule_sshd_use_strong_kex medium

Use Only Strong Key Exchange algorithms

Rule IDxccdf_org.ssgproject.content_rule_sshd_use_strong_kex
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  Req-2.2.7, 5.2.15

Description

Limit the Key Exchange to strong algorithms. The following line in /etc/ssh/sshd_config demonstrates use of those:

KexAlgorithms ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256

Rationale

Key exchange is any method in cryptography by which cryptographic keys are exchanged between two parties, allowing use of a cryptographic algorithm. If the sender and receiver wish to exchange encrypted messages, each must be equipped to encrypt messages to be sent and decrypt messages received

Use Only Strong MACsxccdf_org.ssgproject.content_rule_sshd_use_strong_macs medium

Use Only Strong MACs

Rule IDxccdf_org.ssgproject.content_rule_sshd_use_strong_macs
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  5.2.14

Description

Limit the MACs to strong hash algorithms. The following line in /etc/ssh/sshd_config demonstrates use of those MACs:

MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512,hmac-sha2-256

Rationale

MD5 and 96-bit MAC algorithms are considered weak and have been shown to increase exploitability in SSH downgrade attacks. Weak algorithms continue to have a great deal of attention as a weak spot that can be exploited with expanded computing power. An attacker that breaks the algorithm could take advantage of a MiTM position to decrypt the SSH tunnel and capture credentials and information

Verify Group Who Owns SSH Server config filexccdf_org.ssgproject.content_rule_file_groupowner_sshd_config medium

Verify Group Who Owns SSH Server config file

Rule IDxccdf_org.ssgproject.content_rule_file_groupowner_sshd_config
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.2.1

Description

To properly set the group owner of /etc/ssh/sshd_config, run the command:

$ sudo chgrp root /etc/ssh/sshd_config

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.

Verify Owner on SSH Server config filexccdf_org.ssgproject.content_rule_file_owner_sshd_config medium

Verify Owner on SSH Server config file

Rule IDxccdf_org.ssgproject.content_rule_file_owner_sshd_config
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.2.1

Description

To properly set the owner of /etc/ssh/sshd_config, run the command:

$ sudo chown root /etc/ssh/sshd_config 

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.

Verify Permissions on SSH Server config filexccdf_org.ssgproject.content_rule_file_permissions_sshd_config medium

Verify Permissions on SSH Server config file

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_sshd_config
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, SRG-OS-000480-GPOS-00227, 5.2.1

Description

To properly set the permissions of /etc/ssh/sshd_config, run the command:

$ sudo chmod 0600 /etc/ssh/sshd_config

Rationale

Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.

Verify Permissions on SSH Server Private *_key Key Filesxccdf_org.ssgproject.content_rule_file_permissions_sshd_private_key medium

Verify Permissions on SSH Server Private *_key Key Files

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_sshd_private_key
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  BP28(R36), 12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.1.13, 3.13.10, CCI-000366, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-2.2.6, SRG-OS-000480-GPOS-00227, 5.2.2

Description

SSH server private keys - files that match the /etc/ssh/*_key glob, have to have restricted permissions. If those files are owned by the root user and the root group, they have to have the 0600 permission or stricter.

Rationale

If an unauthorized user obtains the private SSH host key file, the host could be impersonated.

Verify Permissions on SSH Server Public *.pub Key Filesxccdf_org.ssgproject.content_rule_file_permissions_sshd_pub_key medium

Verify Permissions on SSH Server Public *.pub Key Files

Rule IDxccdf_org.ssgproject.content_rule_file_permissions_sshd_pub_key
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  12, 13, 14, 15, 16, 18, 3, 5, APO01.06, DSS05.04, DSS05.07, DSS06.02, 3.1.13, 3.13.10, CCI-000366, 4.3.3.7.3, SR 2.1, SR 5.2, A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, AC-17(a), CM-6(a), AC-6(1), PR.AC-4, PR.DS-5, Req-2.2.6, SRG-OS-000480-GPOS-00227, 5.2.3

Description

To properly set the permissions of /etc/ssh/*.pub, run the command:

$ sudo chmod 0644 /etc/ssh/*.pub

Rationale

If a public host key file is modified by an unauthorized user, the SSH service may be compromised.

Remove the X Windows Package Groupxccdf_org.ssgproject.content_rule_package_xorg-x11-server-common_removed medium

Remove the X Windows Package Group

Rule IDxccdf_org.ssgproject.content_rule_package_xorg-x11-server-common_removed
Result
pass
Time2024-04-05T12:59:33
Severitymedium
Identifiers and References

References:  12, 15, 8, APO13.01, DSS01.04, DSS05.02, DSS05.03, CCI-000366, 4.3.3.6.6, SR 1.13, SR 2.6, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6, A.11.2.6, A.13.1.1, A.13.2.1, A.14.1.3, A.6.2.1, A.6.2.2, CM-7(a), CM-7(b), CM-6(a), PR.AC-3, PR.PT-4, SRG-OS-000480-GPOS-00227, 2.2.1

Description

By removing the xorg-x11-server-common package, the system no longer has X Windows installed. If X Windows is not installed then the system cannot boot into graphical user mode. This prevents the system from being accidentally or maliciously booted into a graphical.target mode. To do so, run the following command:

$ sudo apt_get groupremove "X Window System"
$ sudo apt_get remove xorg-x11-server-common

Rationale

Unnecessary service packages must not be installed to decrease the attack surface of the system. X windows has a long history of security vulnerabilities and should not be installed unless approved and documented.

Warnings
warning  The installation and use of a Graphical User Interface (GUI) increases your attack vector and decreases your overall security posture. Removing the package xorg-x11-server-common package will remove the graphical target which might bring your system to an inconsistent state requiring additional configuration to access the system again. If a GUI is an operational requirement, a tailored profile that removes this rule should used before continuing installation.
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