A PolicyKit security update has been released for Ubuntu 20.04 LTS and 21.10.

==========================================================================
Ubuntu Security Notice USN-5304-1
February 28, 2022

policykit-1 vulnerability
==========================================================================

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

- Ubuntu 21.10
- Ubuntu 20.04 LTS

Summary:

policykit-1 could be made to crash if it received specially crafted data.

Software Description:
- policykit-1: framework for managing administrative policies and privileges

Details:

Kevin Backhouse discovered that PolicyKit incorrectly handled file
descriptors. A local attacker could possibly use this issue to cause
PolicyKit to crash, resulting in a denial of service.

Update instructions:

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

Ubuntu 21.10:
policykit-1 0.105-31ubuntu0.2

Ubuntu 20.04 LTS:
policykit-1 0.105-26ubuntu1.3

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

References:
  https://ubuntu.com/security/notices/USN-5304-1
CVE-2021-4115

Package Information:
  https://launchpad.net/ubuntu/+source/policykit-1/0.105-31ubuntu0.2
  https://launchpad.net/ubuntu/+source/policykit-1/0.105-26ubuntu1.3