Ubuntu Update for xorg-server USN-1232-1

Summary
Ubuntu Update for Linux kernel vulnerabilities USN-1232-1
Solution
Please Install the Updated Packages.
Insight
It was discovered that the X server incorrectly handled certain malformed input. An authorized attacker could exploit this to cause the X server to crash, leading to a denial or service, or possibly execute arbitrary code with root privileges. This issue only affected Ubuntu 10.04 LTS and 10.10. (CVE-2010-4818) It was discovered that the X server incorrectly handled certain malformed input. An authorized attacker could exploit this to cause the X server to crash, leading to a denial or service, or possibly read arbitrary data from the X server process. This issue only affected Ubuntu 10.04 LTS. (CVE-2010-4819) Vladz discovered that the X server incorrectly handled lock files. A local attacker could use this flaw to determine if a file existed or not. (CVE-2011-4028) Vladz discovered that the X server incorrectly handled setting lock file permissions. A local attacker could use this flaw to gain read permissions on arbitrary files and view sensitive information. (CVE-2011-4029)
Affected
xorg-server on Ubuntu 11.04 , Ubuntu 10.10 , Ubuntu 10.04 LTS