==========================================================================
Ubuntu Security Notice USN-7299-3
March 12, 2025

xorg-server, xwayland regression
==========================================================================

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

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

USN-7299-2 caused a regression in X.Org X Server.

Software Description:
- xorg-server: X.Org X11 server
- xorg-server-hwe-18.04: X.Org X11 server
- xorg-server-hwe-16.04: X.Org X11 server

Details:

USN-7299-2 fix vulnerabilities in X.Org X Server. This fix caused
regression in Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. This update
reverts it pending further investigation.

Original advisory details:

 Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled
 certain memory operations. An attacker could use these issues to cause the
 X Server to crash, leading to a denial of service, or possibly execute
 arbitrary code.

Update instructions:

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

Ubuntu 18.04 LTS
  xserver-xorg-core               2:1.19.6-1ubuntu4.15+esm11
                                  Available with Ubuntu Pro
  xserver-xorg-core-hwe-18.04     2:1.20.8-2ubuntu2.2~18.04.11+esm3
                                  Available with Ubuntu Pro
  xwayland                        2:1.19.6-1ubuntu4.15+esm11
                                  Available with Ubuntu Pro
  xwayland-hwe-18.04              2:1.20.8-2ubuntu2.2~18.04.11+esm3
                                  Available with Ubuntu Pro

Ubuntu 16.04 LTS
  xserver-xorg-core               2:1.18.4-0ubuntu0.12+esm16
                                  Available with Ubuntu Pro
  xserver-xorg-core-hwe-16.04     2:1.19.6-1ubuntu4.1~16.04.6+esm8
                                  Available with Ubuntu Pro
  xwayland                        2:1.18.4-0ubuntu0.12+esm16
                                  Available with Ubuntu Pro
  xwayland-hwe-16.04              2:1.19.6-1ubuntu4.1~16.04.6+esm8
                                  Available with Ubuntu Pro

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

References:
  https://ubuntu.com/security/notices/USN-7299-3
  https://ubuntu.com/security/notices/USN-7299-2
  https://ubuntu.com/security/notices/USN-7299-1
  https://launchpad.net/bugs/2101897