A Sudo security update has been released for Ubuntu Linux 16.04 ESM.

USN-5811-2: Sudo vulnerability

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Ubuntu Security Notice USN-5811-2
January 18, 2023

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

- Ubuntu 16.04 ESM

Summary:

Sudo could be made to possibly edit arbitrary files
if it received a specially crafted input.

Software Description:
- sudo: Provide limited super user privileges to specific users

Details:

USN-5811-1 fixed a vulnerability in Sudo. This update provides
the corresponding update for Ubuntu 16.04 ESM.

Original advisory details:

Matthieu Barjole and Victor Cutillas discovered that Sudo incorrectly
handled user-specified editors when using the sudoedit command. A local
attacker that has permission to use the sudoedit command could possibly use
this issue to edit arbitrary files. (CVE-2023-22809)

Update instructions:

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

Ubuntu 16.04 ESM:
sudo 1.8.16-0ubuntu1.10+esm1
sudo-ldap 1.8.16-0ubuntu1.10+esm1

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

References:
  https://ubuntu.com/security/notices/USN-5811-2
  https://ubuntu.com/security/notices/USN-5811-1
CVE-2023-22809