A GLib security update has been released for Ubuntu Linux 14.04 ESM, 16.04 ESM, and 18.04 LTS.

USN-5189-1: GLib vulnerability

==========================================================================
Ubuntu Security Notice USN-5189-1
December 13, 2021

A security issue was fixed in GLib
==========================================================================

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

- Ubuntu 18.04 LTS
- Ubuntu 16.04 ESM
- Ubuntu 14.04 ESM

Summary:

GLib could be used to escalate privilege if it received specially crafted
input.

Software Description:
- glib2.0: GLib library of C routines

Details:

It was discovered that GLib incorrectly handled certain environment variables.
An attacker could possibly use this issue to escalate privileges.

Update instructions:

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

Ubuntu 18.04 LTS:
libglib2.0-0 2.56.4-0ubuntu0.18.04.9
libglib2.0-bin 2.56.4-0ubuntu0.18.04.9
libglib2.0-data 2.56.4-0ubuntu0.18.04.9
libglib2.0-dev 2.56.4-0ubuntu0.18.04.9

Ubuntu 16.04 ESM:
libglib2.0-0 2.48.2-0ubuntu4.8+esm1
libglib2.0-bin 2.48.2-0ubuntu4.8+esm1
libglib2.0-data 2.48.2-0ubuntu4.8+esm1
libglib2.0-dev 2.48.2-0ubuntu4.8+esm1

Ubuntu 14.04 ESM:
libglib2.0-0 2.40.2-0ubuntu1.1+esm4
libglib2.0-bin 2.40.2-0ubuntu1.1+esm4
libglib2.0-data 2.40.2-0ubuntu1.1+esm4
libglib2.0-dev 2.40.2-0ubuntu1.1+esm4

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

References:
https://ubuntu.com/security/notices/USN-5189-1
CVE-2021-3800

Package Information:
https://launchpad.net/ubuntu/+source/glib2.0/2.56.4-0ubuntu0.18.04.9