CVE-2013-220 - out-of-bounds reads in autofs and ssh responder

Bug #1105898 reported by Timo Aaltonen on 2013-01-26
260
This bug affects 1 person
Affects Status Importance Assigned to Milestone
sssd (Ubuntu)
Undecided
Unassigned
Precise
Medium
Unassigned
Quantal
Medium
Timo Aaltonen

Bug Description

================= A security bug in SSSD 1.8 and 1.9 ===============
=
= Subject: out-of-bounds reads in autofs and ssh responder
=
= CVE ID#: CVE-2013-0220
=
= Summary: Multiple out-of-bounds buffer read flaws were found in
= the way the autofs and ssh responders of the SSSD
= performed the parsing of input packet values. An attacker
= could crash the autofs and ssh responders with the use
= of a carefully crafted packet written to the responder
= sockets.
=
=
= Impact: low
=
= Acknowledgements: The bug was found by Florian Weimer of the Red Hat
= Product Security team
=
= Affects default
= configuration: yes (as generated by ipa-client-install)
=
= Introduced with: 1.8.0
=
===============================================================

==== DESCRIPTION ====

SSSD versions 1.8.0 through 1.9.3 are vulnerable to a security bug.

The functions that parse the incoming data packet from client applications
in both the ssh and autofs responders do not check the string lengths against
the packet length correctly. An attacker could exploit the bug and crash
the autofs or the ssh responder with the use of a specially crafted packet
sent to the responder sockets, causing a temporary denial of service.

If you are not using the autofs or SSH integration, you can disable the
vulnerable responders by removing "ssh" or "autofs" respectively from the
list of services configured in the [sssd] section of the SSSD config file.

The default configuration of a client of FreeIPA - as generated by
ipa-client-install - is affected because the ssh responder is enabled
by default.

The fix will be delivered as part of the upcoming 1.9.4 release. There won't
be a separate 1.9 security release as the 1.9.4 version will be released later
this week. The flaw will be fixed in a separate release for the 1.8 and 1.5 LTM
releases as well.

The bug is being tracked in the following Red Hat Bugzilla report:
https://bugzilla.redhat.com/show_bug.cgi?id=884601

==== PATCH AVAILABILITY ====

The patch is available at:
http://git.fedorahosted.org/cgit/sssd.git/patch/?id=2bd514cfde1938b1e245af11c9b548d58d49b325

Timo Aaltonen (tjaalton) wrote :

fixed for raring in 1.9.3-0ubuntu2

Changed in sssd (Ubuntu):
status: New → Fix Released
Changed in sssd (Ubuntu Precise):
importance: Undecided → Medium
status: New → In Progress
Changed in sssd (Ubuntu Quantal):
assignee: nobody → Timo Aaltonen (tjaalton)
importance: Undecided → Medium
status: New → In Progress

Hello Timo, or anyone else affected,

Accepted sssd into precise-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/sssd/1.8.6-0ubuntu0.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Changed in sssd (Ubuntu Precise):
status: In Progress → Fix Committed
tags: added: verification-needed
Changed in sssd (Ubuntu Quantal):
status: In Progress → Fix Committed
Adam Conrad (adconrad) wrote :

Hello Timo, or anyone else affected,

Accepted sssd into quantal-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/sssd/1.9.1-0ubuntu1.2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Timo Aaltonen (tjaalton) on 2013-02-27
tags: added: verification-done
removed: verification-needed
Timo Aaltonen (tjaalton) on 2013-03-12
Changed in sssd (Ubuntu Quantal):
status: Fix Committed → Fix Released
Timo Aaltonen (tjaalton) wrote :

This bug was fixed in the package sssd - 1.8.6-0ubuntu0.2

---------------
sssd (1.8.6-0ubuntu0.2) precise-proposed; urgency=low

  * rules: Really install the new pam-auth-update file for password
    changes. (LP: #1086272)
  * rules: Pass --datadir, so the path in autogenerated python files is
    correctly substituted. (LP: #1079938)

Changed in sssd (Ubuntu Precise):
status: Fix Committed → Fix Released
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