Skulltag 0.96f and prior suffers from a format string vulnerability exploitable when a client passes a wrong version string.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/45824/Skulltag0.96f.txt
Source: https://packetstormsecurity.com/files/45824/Skulltag0.96f.txt.html