==========================================================================
Ubuntu Security Notice USN-6555-1
December 13, 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.

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 XKB
button actions. An attacker could possibly use this issue to cause the X
Server to crash, execute arbitrary code, or escalate privileges.
(CVE-2023-6377)

Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled
memory when processing the RRChangeOutputProperty and
RRChangeProviderProperty APIs. An attacker could possibly use this issue to
cause the X Server to crash, or obtain sensitive information.
(CVE-2023-6478)

Update instructions:

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

Ubuntu 23.10:
   xserver-xorg-core               2:21.1.7-3ubuntu2.4
   xwayland                        2:23.2.0-1ubuntu0.3

Ubuntu 23.04:
   xserver-xorg-core               2:21.1.7-1ubuntu3.4
   xwayland                        2:22.1.8-1ubuntu1.3

Ubuntu 22.04 LTS:
   xserver-xorg-core               2:21.1.4-2ubuntu1.7~22.04.5
   xwayland                        2:22.1.1-1ubuntu0.9

Ubuntu 20.04 LTS:
   xserver-xorg-core               2:1.20.13-1ubuntu1~20.04.12
   xwayland                        2:1.20.13-1ubuntu1~20.04.12

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

References:
   https://ubuntu.com/security/notices/USN-6555-1
   CVE-2023-6377, CVE-2023-6478

Package Information:
   https://launchpad.net/ubuntu/+source/xorg-server/2:21.1.7-3ubuntu2.4
   https://launchpad.net/ubuntu/+source/xwayland/2:23.2.0-1ubuntu0.3
   https://launchpad.net/ubuntu/+source/xorg-server/2:21.1.7-1ubuntu3.4
   https://launchpad.net/ubuntu/+source/xwayland/2:22.1.8-1ubuntu1.3
   https://launchpad.net/ubuntu/+source/xorg-server/2:21.1.4-2ubuntu1.7~22.04.5
   https://launchpad.net/ubuntu/+source/xwayland/2:22.1.1-1ubuntu0.9
   https://launchpad.net/ubuntu/+source/xorg-server/2:1.20.13-1ubuntu1~20.04.12