Avast! Antivirus is prone to a local privilege-escalation vulnerability. Local attackers can exploit this issue to execute arbitrary code with superuser privileges and completely compromise the affected computer. Failed exploit attempts will result in a denial-of-service condition.

Go here to see the original: <a href="http://msmvps.com/blogs/donna/archive/2009/11/19/avast-antivirus-aswrdr-sys-driver-local-privilege-escalation-vulner