CVE-2020-6017
📋 TL;DR
CVE-2020-6017 is a heap-based buffer overflow vulnerability in Valve's Game Networking Sockets library that allows remote attackers to execute arbitrary code or cause denial of service. It affects applications using vulnerable versions of the library with plain-text messaging enabled. This primarily impacts game servers and applications built with Valve's networking technology.
💻 Affected Systems
- Valve Game Networking Sockets library
- Applications using vulnerable versions of the library
📦 What is this software?
Game Networking Sockets by Valvesoftware
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or persistent backdoor installation.
Likely Case
Denial of service through application crashes or memory corruption, potentially disrupting game services.
If Mitigated
Limited impact if plain-text messaging is disabled or network access is restricted.
🎯 Exploit Status
Detailed technical analysis and proof-of-concept available in Check Point research. Exploitation requires sending specially crafted unreliable segments.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v1.2.0 and later
Vendor Advisory: https://github.com/ValveSoftware/GameNetworkingSockets/commit/e0c86dcb9139771db3db0cfdb1fb8bef0af19c43
Restart Required: Yes
Instructions:
1. Update GameNetworkingSockets library to v1.2.0 or later. 2. Recompile applications with the updated library. 3. Restart affected services.
🔧 Temporary Workarounds
Disable plain-text messaging
allConfigure GameNetworkingSockets to use only encrypted connections, which are not vulnerable.
Network segmentation
allRestrict network access to vulnerable services using firewalls or network policies.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate vulnerable systems
- Deploy intrusion detection/prevention systems to monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check if GameNetworkingSockets library version is below v1.2.0 and plain-text messaging is enabled.Check Version:
Check library version in source code or compiled binaries; no universal command exists as implementation varies by application.Verify Fix Applied:
Confirm library version is v1.2.0 or later and verify applications are using the updated library.📡 Detection & Monitoring
Log Indicators:
- Application crashes with memory corruption errors
- Unusual network traffic patterns with long unreliable segments
Network Indicators:
- Malformed packets targeting SNP_ReceiveUnreliableSegment function
- Excessive plain-text message traffic
SIEM Query:
Search for application crashes related to GameNetworkingSockets or memory corruption events in affected applications.🔗 References
- https://github.com/ValveSoftware/GameNetworkingSockets/commit/e0c86dcb9139771db3db0cfdb1fb8bef0af19c43
- https://research.checkpoint.com/2020/game-on-finding-vulnerabilities-in-valves-steam-sockets/
- https://github.com/ValveSoftware/GameNetworkingSockets/commit/e0c86dcb9139771db3db0cfdb1fb8bef0af19c43
- https://research.checkpoint.com/2020/game-on-finding-vulnerabilities-in-valves-steam-sockets/
