Buffer overflow in a third-party compression library (UNACEV2.DLL), as used in avast! Antivirus Home/Professional Edition 4.6.665 and Server Edition 4.6.460, allows remote attackers to execute arbitrary code via an ACE archive containing a long filename.
Buffer overflow in the Aavmker4 device driver in Avast! Antivirus 4.6 and possibly other versions allows local users to cause a denial of service (system crash) and possibly execute arbitrary code via certain signals combined with crafted input.