#Hacktivity2024 // Hacking CS:GO to Death

CS:GO Attack Surface

The speaker describes hacking Counter-Strike: Global Offensive via its Source engine attack surface. Players can host dedicated servers and upload Workshop maps, enabling client-to-server, client-to-client, and server-to-client attacks. Malicious actors can spin up servers or maps that compromise connecting clients.

Squirrel Mapscript Engine

Vulnerabilities were found in CS:GO's Squirrel scripting engine, used for map logic via mapscript files that run at map load. Valve maintains an old, patched fork with restricted standard library access, but printing certain objects leaks raw pointer values useful for exploitation.

Exploitation and Findings

The talk covers building a Squirrel script that runs locally on the victim machine to achieve remote code execution. Bugs include integer division edge cases (DoS only), pointer leaks via print, and additional issues including two CS:GO zero-days and one Squirrel zero-day. Some overlapped with prior public research.

Disclosure Notes

The speaker shares observations on the vulnerability disclosure process, consistent with prior CS:GO security talks.