This vulnerability allows local attackers to execute arbitrary code in kernel space on vulnerable installations of Sophos Anti-Virus. Local access to the system is required to leverage the vulnerability. The specific flaw exists in the handling of the system call NtQueryAttributesFile by the filter driver savonaccessfilter.sys. Due to improper handling of parameters to the function pool corruption can occur in kernel space. A local attacker can leverage this to execute arbitrary code in ring 0.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/90555/TPTI-10-03.txt
Source: https://packetstormsecurity.com/files/90555/Sophos-Anti-Virus-SAVOnAccessFilter-Local-Privilege-Escalation.html