AVG Internet Security

Local privilege escalation vulnerability in AVG Internet Security

The TDI driver (avgtdix.sys) in AVG Internet Security before 2013.3495 Hot Fix 18 and 2015.x before 2015.5315 and Protection before 2015.5315 allows local users to write to arbitrary memory locations, and consequently gain privileges, via a crafted 0x830020f8 IOCTL call.

Code injection vulnerability in AVG Ultimate 17.1 (and earlier), AVG Internet Security 17.1 (and earlier), and AVG AntiVirus FREE 17.1 (and earlier) allows a local attacker to bypass a self-protection mechanism, inject arbitrary code, and take full control of any AVG process via a "DoubleAgent" attack. One perspective on this issue is that (1) these products do not use the Protected Processes feature, and therefore an attacker can enter an arbitrary Application Verifier Provider DLL under Image File Execution Options in the registry; (2) the self-protection mechanism is intended to block all local processes (regardless of privileges) from modifying Image File Execution Options for these products; and (3) this mechanism can be bypassed by an attacker who temporarily renames Image File Execution Options during the attack.

AVG Internet Security 2015 allocates memory with Read, Write, Execute (RWX) permissions at predictable addresses when protecting user-mode processes, which allows attackers to bypass the DEP and ASLR protection mechanisms via unspecified vectors.

Race condition in AVG Internet Security 9.0.791 on Windows XP allows local users to bypass kernel-mode hook handlers, and execute dangerous code that would otherwise be blocked by a handler but not blocked by signature-based malware detection, via certain user-space memory changes during hook-handler execution, aka an argument-switch attack or a KHOBE attack. NOTE: this issue is disputed by some third parties because it is a flaw in a protection mechanism for situations where a crafted program has already begun to execute