Vigil@nce: RealVNC, denial of service via ClientCutText
May 2010 by Vigil@nce
This bulletin was written by Vigil@nce : http://vigilance.fr/
SYNTHESIS OF THE VULNERABILITY
An authenticated attacker can send the ClientCutText message to
RealVNC, in order to stop it.
– Severity: 1/4
– Creation date: 05/05/2010
DESCRIPTION OF THE VULNERABILITY
The RealVNC server implements several messages for interface
manipulation:
– ClientCutText : cut a text area
– PointerEvent : a mouse event
– etc.
However, the winvnc4.exe process does not check if the size
indicated in the ClientCutText message is too long.
An authenticated attacker can therefore send the ClientCutText
message to RealVNC, in order to stop it.
ACCESS TO THE COMPLETE VIGIL@NCE BULLETIN
http://vigilance.fr/vulnerability/RealVNC-denial-of-service-via-ClientCutText-9629