Buffer overflow in Valve Software Source Sdk (Source-Sdk-2013)
CVE-2017-20205
Valve's Source SDK (source-sdk-2013)'s ragdoll model parsing logic contains a stack-based buffer overflow vulnerability.The tokenizer function `nexttoken` copies characters from an input string into a fixed-size stack buffer without performing bounds checks. When `ParseKeyValue` processes a collisionpair rule longer than the destination buffer (256 bytes), an overflow of the stack buffer `szToken` can occur and overwrite the function return address. A remote attacker can trigger the vulnerable code by supplying a specially crafted ragdoll model which causes the oversized collisionpair rule to be parsed, resulting in remote code execution on affected clients or servers. Valve has addressed this issue in many of their Source games, but independently-developed games must manually apply patch.
Vulnerability class: Buffer Overflow
Published · last modified .
EPSS exploit prediction
EPSS: 0.007 (51.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.007 · change: +0.000
Affected products
- Valve Software Source Sdk (Source-Sdk-2013) — versions source-sdk-2013
Weakness classification (CWE)
References
- www.oneupsecurity.com/research/remote-code-execution-in-source-games/ (technical-description, patch)
- github.com/ValveSoftware/source-sdk-2013 (product)
- www.vulncheck.com/advisories/valve-source-sdk-stack-based-buffer-overflow-rce (third-party-advisory)