Ubuntu Security Notice USN-4171-6

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

apport regression
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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://usn.ubuntu.com/4171-6
https://usn.ubuntu.com/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