X could be made to start by a user who lacked appropriate permissions.
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.
26 January 2012
A security issue affects these releases of Ubuntu and its derivatives:
X could be made to start by a user who lacked appropriate permissions.
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.
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.
In general, a standard system update will make all the necessary changes.
Vulmon