Vigil@nce: KDE, unlocking KRunner lock module
February 2010 by Vigil@nce
A local attacker can stop KDE KScreenSaver by pressing on a key, in order to access to user’s session.
Consequences: user access/rights
Provenance: user console
Means of attack: 1 attack
Ability of attacker: technician (2/4)
Confidence: confirmed by the editor (5/5)
Diffusion of the vulnerable configuration: high (3/3)
Creation date: 12/02/2010
Revision date: 18/02/2010
Unix - plateform
DESCRIPTION OF THE VULNERABILITY
The KScreenSaver program locks the screen and displays a drawing. It uses the KRunner Lock module.
The KRunner Lock module creates a new process to check the password. However, if the attacker quickly presses on the Return key, two processes can exist in parallel. The second process thus uses resources which are not available, and stops KScreenSaver.
A local attacker can therefore stop KDE KScreenSaver by pressing on Return key several times per second, in order to access to user’s session.
Identifiers: 217882, 226449, 579280, advisory-20100217-1,