source: http://www.securityfocus.com/bid/25423/info

Skulltag is prone to a remote heap-based buffer-overflow vulnerability because it fails to perform adequate boundary-checks on user-supplied input.

Attackers can exploit this issue to execute arbitrary code with the privileges of the user running the application. Successful exploits may compromise affected computers. Failed attacks will likely cause denial-of-service conditions.

Skulltag 0.97d-beta4.1 is vulnerable; other versions may also be affected. 

http://www.exploit-db.com/sploits/30523.zip