A local privilege escalation vulnerability exists in Agnitum Outpost Internet Security 8.1 that allows an unprivileged user to execute arbitrary code with SYSTEM privileges. The flaw resides in the acs.exe component, which exposes a named pipe that accepts unauthenticated commands. By exploiting a directory traversal weakness in the pipe protocol, an attacker can instruct the service to load a malicious DLL from a user-controlled location. The DLL is then executed in the context of the privileged service.
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.