==========================================================================
Ubuntu Security Notice USN-6571-1
January 09, 2024

monit vulnerability

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

• Ubuntu 22.04 LTS (Available with Ubuntu Pro)
• Ubuntu 20.04 LTS (Available with Ubuntu Pro)
• Ubuntu 18.04 LTS (Available with Ubuntu Pro)
• Ubuntu 16.04 LTS (Available with Ubuntu Pro)
• Ubuntu 14.04 LTS (Available with Ubuntu Pro)

Summary:

Monit could be made to bypass authentication checks for disabled accounts.

Software Description:

• monit: utility for monitoring and managing daemons or similar programs

Details:

Youssef Rebahi-Gilbert discovered that Monit did not properly process
credentials for disabled accounts. An attacker could possibly use this
issue to login to the platform with an expired account and a valid
password.

Update instructions:

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

Ubuntu 22.04 LTS (Available with Ubuntu Pro):
monit 1:5.31.0-1ubuntu0.1~esm1

Ubuntu 20.04 LTS (Available with Ubuntu Pro):
monit 1:5.26.0-4ubuntu0.1~esm1

Ubuntu 18.04 LTS (Available with Ubuntu Pro):
monit 1:5.25.1-1ubuntu0.1~esm2

Ubuntu 16.04 LTS (Available with Ubuntu Pro):
monit 1:5.16-2ubuntu0.2+esm2

Ubuntu 14.04 LTS (Available with Ubuntu Pro):
monit 1:5.6-2ubuntu0.1+esm3

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

References:
https://ubuntu.com/security/notices/USN-6571-1
CVE-2022-26563