I have found a security issue on apport 2.20.11 and earlier.
## Vulnerability in apport
apport 2.20.11 and earlier have an unhandled exception vulnerability during parsing apport-ignore.xml.
An attacker can cause a denial of service (i.e., application crash) via a crafted apport-ignore.xml file.
## Description
Reports can be suppressed by blacklisting in apport-ignore.xml.
Here is /var/log/apport.log when the above exception occurs.
ERROR: apport (pid 25904) Tue May 5 18:38:21 2020: Unhandled exception:
Traceback (most recent call last):
File "/usr/share/apport/apport", line 629, in <module>
if info.check_ignored():
File "/usr/lib/python3/dist-packages/apport/report.py", line 1082, in check_ignored
if float(ignore.getAttribute('mtime')) >= cur_mtime:
ValueError: could not convert string to float: 'string'
Hi,
I have found a security issue on apport 2.20.11 and earlier.
## Vulnerability in apport
apport 2.20.11 and earlier have an unhandled exception vulnerability during parsing apport-ignore.xml.
An attacker can cause a denial of service (i.e., application crash) via a crafted apport-ignore.xml file.
## Description
Reports can be suppressed by blacklisting in apport-ignore.xml.
This is an example of apport-ignore.xml
<?xml version="1.0" ?> "/opt/sublime_ text/sublime_ text"/> "/bin/sleep" /> "/usr/bin/ strace" />
<apport>
<ignore mtime="1461374304" program=
<ignore mtime="1453471676" program=
<ignore mtime="1452699271" program=
</apport>
Unfortunately, it may cause an unhandled exception when 'mtime' attribute is specified as a string value, not a number like this.
<?xml version="1.0" ?> "/bin/sleep" />
<apport>
<ignore mtime="string" program=
</apport>
It may disrupt apport service and allow an attacker to potentially enable a denial of service via local access.
The flaw lies in improper exception handling of 'mtime' attribute in apport-ignore.xml (see https:/ /git.launchpad. net/ubuntu/ +source/ apport/ tree/apport/ report. py?h=applied/ ubuntu/ devel#n1104).
Here is /var/log/apport.log when the above exception occurs.
ERROR: apport (pid 25904) Tue May 5 18:38:21 2020: Unhandled exception: apport/ apport" , line 629, in <module> ignored( ): python3/ dist-packages/ apport/ report. py", line 1082, in check_ignored getAttribute( 'mtime' )) >= cur_mtime:
Traceback (most recent call last):
File "/usr/share/
if info.check_
File "/usr/lib/
if float(ignore.
ValueError: could not convert string to float: 'string'
Sincerely,