Ubuntu: 1349-1: X.Org vulnerability
Posted by Benjamin D. Thomas   
Ubuntu X could be made to start by a user who lacked appropriate permissions.
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Ubuntu Security Notice USN-1349-1
January 26, 2012

xorg vulnerability
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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:

X could be made to start by a user who lacked appropriate permissions.

Software Description:
- xorg: X.Org X Window System

Details:

It was discovered that the X wrapper incorrectly checked certain console
permissions when launched by unprivileged users. An attacker connected
remotely could use this flaw to start X, bypassing the console permissions
check.

Update instructions:

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

Ubuntu 11.10:
  xserver-xorg                    1:7.6+7ubuntu7.1

Ubuntu 11.04:
  xserver-xorg                    1:7.6+4ubuntu3.2

Ubuntu 10.10:
  xserver-xorg                    1:7.5+6ubuntu3.1

Ubuntu 10.04 LTS:
  xserver-xorg                    1:7.5+5ubuntu1.1

In general, a standard system update will make all the necessary changes.

References:
  http://www.ubuntu.com/usn/usn-1349-1
  CVE-2011-4613

Package Information:
  https://launchpad.net/ubuntu/+source/xorg/1:7.6+7ubuntu7.1
  https://launchpad.net/ubuntu/+source/xorg/1:7.6+4ubuntu3.2
  https://launchpad.net/ubuntu/+source/xorg/1:7.5+6ubuntu3.1
  https://launchpad.net/ubuntu/+source/xorg/1:7.5+5ubuntu1.1