A X.Org X Server security update has been released for Ubuntu Linux 14.04 ESM.

USN-4488-2: X.Org X Server vulnerabilities

==========================================================================
Ubuntu Security Notice USN-4488-2
September 09, 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-4488-1 fixed several vulnerabilities in X.Org. This update provides
the corresponding update and also the update from USN-4490-1 for Ubuntu 14.04 ESM.

Original advisory details:

Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled the
input extension protocol. A local attacker could possibly use this issue to
escalate privileges. (CVE-2020-14346)

Jan-Niklas Sohn discovered that the X.Org X Server incorrectly initialized
memory. A local attacker could possibly use this issue to obtain sensitive
information. (CVE-2020-14347)

Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled the
XkbSelectEvents function. A local attacker could possibly use this issue to
escalate privileges. (CVE-2020-14361)

Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled the
XRecordRegisterClients function. A local attacker could possibly use this
issue to escalate privileges. (CVE-2020-14362)

Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled the
XkbSetNames function. A local attacker could possibly use this issue to
escalate privileges. (CVE-2020-14345)

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+esm2

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

References:
  https://usn.ubuntu.com/4488-2
  https://usn.ubuntu.com/4488-1
CVE-2020-14345, CVE-2020-14346, CVE-2020-14347, CVE-2020-14361,
CVE-2020-14362