Hello, We would like to inform you about a vulnerability in Outpost Firewall PRO 4.0. Description: Outpost insufficiently protects its own mutex outpost_ipc_hdr. Arbitrary process is able to open and capture this mutex. In such case, Outpost is not able to use this mutex for its synchronization and its internal mechanisms lock when they try to use it. Outpost uses this mutex every time a potentially dangerous operation is executed. For example, this results in an impossibility of running new processes while the mutex is locked. After the mutex is released, all blocked operations completes. However, the release can not be enforced. User is thus forced to reboot the system. Vulnerable software: * Outpost Firewall PRO 4.0 (1007.591.145) * Outpost Firewall PRO 4.0 (964.582.059) * probably all older versions of Outpost Firewall PRO 4.0 * possibly older versions of Outpost Firewall PRO More details and a proof of concept including its source code are available here: http://www.matousec.com/info/advisories/Outpost-Enforcing-system-reboot- with-outpost_ipc_hdr-mutex.php Regards, -- Matousec - Transparent security Research http://www.matousec.com/