A PolicyKit security update has been released for Ubuntu Linux 14.04 ESM and 16.04 ESM.

USN-5252-2: PolicyKit vulnerability

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Ubuntu Security Notice USN-5252-2
January 25, 2022

policykit-1 vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 ESM
- Ubuntu 14.04 ESM

Summary:

policykit-1 could be made to run programs as an administrator.

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

Details:

USN-5252-1 fixed a vulnerability in policykit-1. This update provides
the corresponding update for Ubuntu 14.04 ESM and Ubuntu 16.04 ESM.

Original advisory details:

It was discovered that the PolicyKit pkexec tool incorrectly handled
command-line arguments. A local attacker could use this issue to escalate
privileges to an administrator.

Update instructions:

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

Ubuntu 16.04 ESM:
policykit-1 0.105-14.1ubuntu0.5+esm1

Ubuntu 14.04 ESM:
policykit-1 0.105-4ubuntu3.14.04.6+esm1

After a standard system update you need to reboot your computer to make all
the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-5252-2
  https://ubuntu.com/security/notices/USN-5252-1
CVE-2021-4034