The X.Org X server could be made to crash or run programs as an administrator if it received specially crafted input.
Pedro Ribeiro discovered that the X.Org X server incorrectly handled memory operations when handling ImageText requests. An attacker could use this issue to cause X.Org to crash, or to possibly execute arbitrary code. (CVE-2013-4396)
17 October 2013
A security issue affects these releases of Ubuntu and its derivatives:
The X.Org X server could be made to crash or run programs as an administrator if it received specially crafted input.
Pedro Ribeiro discovered that the X.Org X server incorrectly handled memory operations when handling ImageText requests. An attacker could use this issue to cause X.Org to crash, or to possibly execute arbitrary code. (CVE-2013-4396)
It was discovered that non-root X.Org X servers such as Xephyr incorrectly used cached xkb files. A local attacker could use this flaw to cause a xkb cache file to be loaded by another user, resulting in a denial of service. (CVE-2013-1056)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to reboot your computer to make all the necessary changes.
Vulmon