mintinstall (aka Software Manager) 7.9.9 for Linux Mint allows code execution if a REVIEWSCACHE file is controlled by an attacker, because an unpickle occurs. This is resolved in 8.0.0 and backports.
Clemens Fries reported that, when using Cinnamon, it was possible to bypass the screensaver lock:
http://seclists.org/oss-sec/2014/q1/327
An attacker with physical access to the machine could use this flaw to take over the locked desktop session.
A patch is currently not yet available.