Avast! versions 4.8 and 5.0 suffer from a aavmker4.sys kernel memory corruption vulnerability.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/86684/TKADV2010-003.txt
Source: https://packetstormsecurity.com/files/86684/Avast-4.8-5.0-Kernel-Memory-Corruption.html