Directory traversal vulnerability 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 write arbitrary files via an ACE archive containing filenames with (1) .. or (2) absolute pathnames.

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.

Heap-based buffer overflow in alwil avast! Anti-virus Engine before 4.7.869 allows remote attackers to execute arbitrary code via a crafted LHA file that contains extended headers with file and directory names whose concatenation triggers the overflow.

avast! Server Edition before 4.7.726 does not demand a password in a certain intended context, even when a password has been set, which allows local users to bypass authentication requirements.