Described by researchers as a “buffer overflow vulnerability,” the exploit was one that had to be loaded onto a victim’s machine through a custom map file. There, the researchers were able to install a custom ragdoll model file, which would, in turn, be loaded up when a player died. But instead of displaying a realistic or comical figure during death, that file executed malicious code.
Discovered by One Up Security, the bug has now been patched by Valve for all affected Source games, including Counterstrike: Global Offensive, TF2, Half-Life 2 Death Match, Portal 2, and Left 4 Dead 2. However, they do suggest that Source mod makers update their mods with the patch linked. One Up Security also provides guidelines and advice for mod makers to help them avoid the potential problems caused by this sort of exploit.
However, users can also take steps to protect themselves from exploits through games. For starters, One Security’s Justin Taft suggests that games should not be installed on work machines. He suggests that gameplay should be maintained on an entirely separate network to business-related functions.
He highlights in his discussion of the bug that this unlikely to be common place, as games are quite a common sight in break rooms and on the home computers of employees — but recommends as much separation as possible to avoid this kind of exploit from affecting corporate interests.
For average gamers who want to add some extra security to their own setup to avoid any potential future exploits that leverage Valve’s popular Source titles, he recommends disabling third-party content with a specific console command. That will leave you unable to enjoy some of the wider variety of custom maps and mods out there, but if security is more important to you than gameplay, it may be worth considering.
