==========================================================================
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