Grisoft AVG Free 7.1, and other versions including 7.0.308, sets Everyone/Full Control permissions for certain update files including (1) upd_vers.cfg, (2) incavi.avm, and (3) unspecified drivers, which might allow local users to gain privileges.

Multiple interpretation error in AVG 7 7.0.323 allows remote attackers to bypass virus scanning via a file such as BAT, HTML, and EML with an "MZ" magic byte sequence which is normally associated with EXE, which causes the file to be treated as a safe type that could still be executed as a dangerous file type by applications on the end system, as demonstrated by a "triple headed" program that contains EXE, EML, and HTML content, aka the "magic byte bug."