A X.Org X Server security update has been released for Ubuntu Linux 20.04 LTS, 22.04 LTS, 23.04, and 23.10.

[USN-6453-1] X.Org X Server vulnerabilities

==========================================================================
Ubuntu Security Notice USN-6453-1
October 25, 2023

xorg-server, xwayland vulnerabilities
==========================================================================

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

- Ubuntu 23.10
- Ubuntu 23.04
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

Summary:

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

Software Description:
- xorg-server: X.Org X11 server
- xwayland: X server for running X clients under Wayland

Details:

Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled
prepending values to certain properties. An attacker could possibly use
this issue to cause the X Server to crash, execute arbitrary code, or
escalate privileges. (CVE-2023-5367)

Sri discovered that the X.Org X Server incorrectly handled detroying
windows in certain legacy multi-screen setups. An attacker could possibly
use this issue to cause the X Server to crash, execute arbitrary code, or
escalate privileges. (CVE-2023-5380)

Update instructions:

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

Ubuntu 23.10:
xserver-xorg-core 2:21.1.7-3ubuntu2.1
xwayland 2:23.2.0-1ubuntu0.1

Ubuntu 23.04:
xserver-xorg-core 2:21.1.7-1ubuntu3.1
xwayland 2:22.1.8-1ubuntu1.1

Ubuntu 22.04 LTS:
xserver-xorg-core 2:21.1.4-2ubuntu1.7~22.04.2
xwayland 2:22.1.1-1ubuntu0.7

Ubuntu 20.04 LTS:
xserver-xorg-core 2:1.20.13-1ubuntu1~20.04.9
xwayland 2:1.20.13-1ubuntu1~20.04.9

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

References:
https://ubuntu.com/security/notices/USN-6453-1
CVE-2023-5367, CVE-2023-5380

Package Information:
https://launchpad.net/ubuntu/+source/xorg-server/2:21.1.7-3ubuntu2.1
https://launchpad.net/ubuntu/+source/xwayland/2:23.2.0-1ubuntu0.1
https://launchpad.net/ubuntu/+source/xorg-server/2:21.1.7-1ubuntu3.1
https://launchpad.net/ubuntu/+source/xwayland/2:22.1.8-1ubuntu1.1
https://launchpad.net/ubuntu/+source/xorg-server/2:21.1.4-2ubuntu1.7~22.04.2
https://launchpad.net/ubuntu/+source/xwayland/2:22.1.1-1ubuntu0.7
https://launchpad.net/ubuntu/+source/xorg-server/2:1.20.13-1ubuntu1~20.04.9