=========================================================================Ubuntu Security Notice USN-4171-6
November 12, 2020

apport regression
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

USN-4171-1 introduced a regression in Apport.

Software Description:
- apport: automatically generate crash reports for debugging

Details:

USN-4171-1 fixed vulnerabilities in Apport. The update caused a regression
when handling configuration files. This update fixes the problem, and also
introduces further hardening measures.

Original advisory details:

 Kevin Backhouse discovered Apport would read its user-controlled settings
 file as the root user. This could be used by a local attacker to possibly
 crash Apport or have other unspecified consequences. (CVE-2019-11481)
  Sander Bos discovered a race-condition in Apport during core dump
 creation. This could be used by a local attacker to generate a crash report
 for a privileged process that is readable by an unprivileged user.
 (CVE-2019-11482)
  Sander Bos discovered Apport mishandled crash dumps originating from
 containers. This could be used by a local attacker to generate a crash
 report for a privileged process that is readable by an unprivileged user.
 (CVE-2019-11483)
  Sander Bos discovered Apport mishandled lock-file creation. This could be
 used by a local attacker to cause a denial of service against Apport.
 (CVE-2019-11485)
  Kevin Backhouse discovered Apport read various process-specific files with
 elevated privileges during crash dump generation. This could could be used
 by a local attacker to generate a crash report for a privileged process
 that is readable by an unprivileged user. (CVE-2019-15790)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 20.10:
  apport                          2.20.11-0ubuntu50.1
  python3-apport                  2.20.11-0ubuntu50.1

Ubuntu 20.04 LTS:
  apport                          2.20.11-0ubuntu27.12
  python3-apport                  2.20.11-0ubuntu27.12

Ubuntu 18.04 LTS:
  apport                          2.20.9-0ubuntu7.20
  python-apport                   2.20.9-0ubuntu7.20
  python3-apport                  2.20.9-0ubuntu7.20

Ubuntu 16.04 LTS:
  apport                          2.20.1-0ubuntu2.27
  python-apport                   2.20.1-0ubuntu2.27
  python3-apport                  2.20.1-0ubuntu2.27

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-4171-6
  https://ubuntu.com/security/notices/USN-4171-1
  https://launchpad.net/bugs/1903332

Package Information:
  https://launchpad.net/ubuntu/+source/apport/2.20.11-0ubuntu50.1
  https://launchpad.net/ubuntu/+source/apport/2.20.11-0ubuntu27.12
  https://launchpad.net/ubuntu/+source/apport/2.20.9-0ubuntu7.20
  https://launchpad.net/ubuntu/+source/apport/2.20.1-0ubuntu2.27