Symantec AntiVirus Corporate Edition 9.0.1.x and 9.0.4.x, and possibly other versions, when obtaining updates from an internal LiveUpdate server, stores sensitive information in cleartext in the Log.Liveupdate log file, which allows attackers to obtain the username and password to the internal LiveUpdate server.
Norton Anti-Virus (NAV) allows remote attackers to bypass content filtering via attachments whose Content-Type and Content-Disposition headers are mixed upper and lower case, which is ignored by some mail clients.
The default configurations for McAfee Virus Scan and Norton Anti-Virus virus checkers do not check files in the RECYCLED folder that is used by the Windows Recycle Bin utility, which allows attackers to store malicious code without detection.