USN-1232-1: X.Org X server vulnerabilities

Ubuntu Security Notice USN-1232-1

18th October, 2011

xorg-server vulnerabilities

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

  • Ubuntu 11.10
  • Ubuntu 11.04
  • Ubuntu 10.10
  • Ubuntu 10.04 LTS

Summary

The X server could be made to crash, run programs as an administrator, or read arbitrary files.

Software description

  • xorg-server - X.Org X server

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 version:

Ubuntu 11.10:
xserver-xorg-core 2:1.10.4-1ubuntu4.1
Ubuntu 11.04:
xserver-xorg-core 2:1.10.1-1ubuntu1.3
Ubuntu 10.10:
xserver-xorg-core 2:1.9.0-0ubuntu7.5
Ubuntu 10.04 LTS:
xserver-xorg-core 2:1.7.6-2ubuntu7.8

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

CVE-2010-4818, CVE-2010-4819, CVE-2011-4028, CVE-2011-4029