=========================================================================
Ubuntu Security Notice USN-4656-2
December 07, 2020

xorg-server vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 14.04 ESM

Summary:

Several security issues were fixed in X.Org X Server.

Software Description:
- xorg-server: X.Org X11 server

Details:

USN-4656-1 fixed several vulnerabilities in X.Org. This update provides
the corresponding update for Ubuntu 14.04 ESM.

Original advisory details:

 Jan-Niklas Sohn discovered that the X.Org X Server XKB extension
 incorrectly handled certain inputs. A local 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 14.04 ESM:
  xserver-xorg-core               2:1.15.1-0ubuntu2.11+esm3

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

References:
  https://usn.ubuntu.com/4656-2
  https://usn.ubuntu.com/4656-1
  CVE-2020-14360, CVE-2020-25712