USN-1232-3: X.Org X server vulnerability

20 October 2011

xorg-server vulnerability

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

  • Ubuntu 10.10
  • Ubuntu 10.04 LTS

Summary

The X server could be made to crash or run programs as an administrator.

Software Description

  • xorg-server - X.Org X server

Details

USN-1232-1 fixed vulnerabilities in the X.Org X server. A regression was found on Ubuntu 10.04 LTS that affected GLX support, and USN-1232-2 was released to temporarily disable the problematic security fix. This update includes a revised fix for CVE-2010-4818.

We apologize for the inconvenience.

Original advisory details:

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)

Update instructions

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

Ubuntu 10.10
xserver-xorg-core - 2:1.9.0-0ubuntu7.6
Ubuntu 10.04 LTS
xserver-xorg-core - 2:1.7.6-2ubuntu7.10

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

After a standard system update you need to restart your session to make all the necessary changes.

References