The X server could be made to reveal keystrokes of other users.
It was discovered that the X.Org X server did not properly clear input events in certain circumstances. A local attacker with physical access could use this flaw to capture keystrokes.
17 April 2013
A security issue affects these releases of Ubuntu and its derivatives:
The X server could be made to reveal keystrokes of other users.
It was discovered that the X.Org X server did not properly clear input events in certain circumstances. A local attacker with physical access could use this flaw to capture keystrokes.
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.
After a standard system update you need to restart your session to make all the necessary changes.
Vulmon