An Apport security update has been released for Ubuntu Linux 16.04 LTS, 18.04 LTS, 20.04 LTS, and 20.10.

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Ubuntu Security Notice USN-4720-1
February 02, 2021

apport vulnerabilities
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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:

Several security issues were fixed in Apport.

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

Details:

Itai Greenhut discovered that Apport incorrectly parsed certain files in
the /proc filesystem. A local attacker could use this issue to escalate
privileges and run arbitrary code. (CVE-2021-25682, CVE-2021-25683)

Itai Greenhut discovered that Apport incorrectly handled opening certain
special files. A local attacker could possibly use this issue to cause
Apport to hang, resulting in a denial of service. (CVE-2021-25684)

Update instructions:

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

Ubuntu 20.10:
apport 2.20.11-0ubuntu50.5
python3-apport 2.20.11-0ubuntu50.5

Ubuntu 20.04 LTS:
apport 2.20.11-0ubuntu27.16
python3-apport 2.20.11-0ubuntu27.16

Ubuntu 18.04 LTS:
apport 2.20.9-0ubuntu7.23
python-apport 2.20.9-0ubuntu7.23
python3-apport 2.20.9-0ubuntu7.23

Ubuntu 16.04 LTS:
apport 2.20.1-0ubuntu2.30
python-apport 2.20.1-0ubuntu2.30
python3-apport 2.20.1-0ubuntu2.30

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

References:
  https://usn.ubuntu.com/4720-1
CVE-2021-25682, CVE-2021-25683, CVE-2021-25684

Package Information:
  https://launchpad.net/ubuntu/+source/apport/2.20.11-0ubuntu50.5
  https://launchpad.net/ubuntu/+source/apport/2.20.11-0ubuntu27.16
  https://launchpad.net/ubuntu/+source/apport/2.20.9-0ubuntu7.23
  https://launchpad.net/ubuntu/+source/apport/2.20.1-0ubuntu2.30