CVE-2020-6016

Name: CVE-2020-6016
Creator: NVD / NIST
Published: 2020-11-18T15:15:13.193+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 5.75%

Last modified Jun 17, 2026

CVE-2020-6016 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Valve's Game Networking Sockets prior to version v1.2.0 improperly handles unreliable segments with negative offsets in function SNP_ReceiveUnreliableSegment(), leading to a Heap-Based Buffer Underflow and a free() of memory not from the heap, resulting in a memory corruption and probably even a remote code execution.. EPSS estimates a 5.75% chance of exploitation in the next 30 days.

Description

Valve's Game Networking Sockets prior to version v1.2.0 improperly handles unreliable segments with negative offsets in function SNP_ReceiveUnreliableSegment(), leading to a Heap-Based Buffer Underflow and a free() of memory not from the heap, resulting in a memory corruption and probably even a remote code execution.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

5.75%

92.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Valvesoftware	Game Networking Sockets	< 1.2.0

References

https://github.com/ValveSoftware/GameNetworkingSockets/commit/e0c86dcb9139771db3db0cfdb1fb8bef0af19c43Patch, Third Party Advisory
https://research.checkpoint.com/2020/game-on-finding-vulnerabilities-in-valves-steam-sockets/Exploit, Third Party Advisory
https://github.com/ValveSoftware/GameNetworkingSockets/commit/e0c86dcb9139771db3db0cfdb1fb8bef0af19c43Patch, Third Party Advisory
https://research.checkpoint.com/2020/game-on-finding-vulnerabilities-in-valves-steam-sockets/Exploit, Third Party Advisory

Timeline

Published: Nov 18, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-6016?

How severe is CVE-2020-6016?

CVE-2020-6016 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 5.75% probability of exploitation in the next 30 days.

How do I fix CVE-2020-6016?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-6016?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST