HOMEVULNERABILITIESCVE-2020-6016
CRITICAL

CVE-2020-6016

CWE-590Published: November 18, 2020· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2020-6016 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

valvesoftware1 product(s)
game networking sockets
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/ValveSoftware/GameNetworkingSockets/commit/e0c86dcb9139771db3db0cfdb1fb8bef0af19c43
PATCHhttps://github.com/ValveSoftware/GameNetworkingSockets/commit/e0c86dcb9139771db3db0cfdb1fb8bef0af19c43
ADVISORYhttps://research.checkpoint.com/2020/game-on-finding-vulnerabilities-in-valves-steam-sockets/
ADVISORYhttps://research.checkpoint.com/2020/game-on-finding-vulnerabilities-in-valves-steam-sockets/

All References (4)

→
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

Quick Facts

CVE IDCVE-2020-6016
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-590
CISA KEVNo
Affected1 vendor(s)
PublishedNov 18, 2020

Related CVEs (CWE-590)

CVE-2022-31627
9.8
CVE-2021-42377
9.8
CVE-2025-32911
9.0
CVE-2022-31625
8.1
CVE-2021-3939
7.8
CVE-2023-22291
7.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-6016 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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