A X.Org X Server security update has been released for Ubuntu Linux 16.04 LTS, 18.04 LTS, 20.04 LTS, and 20.10.
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Ubuntu Security Notice USN-4905-1
April 13, 2021
xorg-server, xorg-server-hwe-16.04, xorg-server-hwe-18.04 vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
Summary:
X.Org X Server could be made to crash or run programs if it received
specially crafted input.
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:
Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled
certain lengths of XInput extension ChangeFeedbackControl requests. An
attacker could use this issue to cause the server to crash, resulting in 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 20.10:
xserver-xorg-core 2:1.20.9-2ubuntu1.3
Ubuntu 20.04 LTS:
xserver-xorg-core 2:1.20.9-2ubuntu1.2~20.04.2
Ubuntu 18.04 LTS:
xserver-xorg-core 2:1.19.6-1ubuntu4.9
xserver-xorg-core-hwe-18.04 2:1.20.8-2ubuntu2.2~18.04.5
Ubuntu 16.04 LTS:
xserver-xorg-core 2:1.18.4-0ubuntu0.12
xserver-xorg-core-hwe-16.04 2:1.19.6-1ubuntu4.1~16.04.6
After a standard system update you need to reboot your computer to make all
the necessary changes.
References:
https://ubuntu.com/security/notices/USN-4905-1
CVE-2021-3472
Package Information:
https://launchpad.net/ubuntu/+source/xorg-server/2:1.20.9-2ubuntu1.3
https://launchpad.net/ubuntu/+source/xorg-server/2:1.20.9-2ubuntu1.2~20.04.2
https://launchpad.net/ubuntu/+source/xorg-server/2:1.19.6-1ubuntu4.9
https://launchpad.net/ubuntu/+source/xorg-server-hwe-18.04/2:1.20.8-2ubuntu2.2~18.04.5
https://launchpad.net/ubuntu/+source/xorg-server/2:1.18.4-0ubuntu0.12
https://launchpad.net/ubuntu/+source/xorg-server-hwe-16.04/2:1.19.6-1ubuntu4.1~16.04.6
