CVE-2021-30481

Valve Steam before 2021-04-17, when a Source engine game is installed, allows remote authenticated users to execute arbitrary code because of a buffer overflow that occurs for a Steam invite after one click.

CVSS v3 8.0 HIGH
CVSS v2.0 6.0 MEDIUM

8.0^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.3 / Impact : 6.0

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

6.0^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:M/Au:S/C:P/I:P/A:P

Exploitability : 6.8 / Impact : 6.4

Access Vector NETWORK

Access Complexity MEDIUM

Authentication SINGLE

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

References

Link	Resource
https://news.ycombinator.com/item?id=26762170	Issue Tracking Third Party Advisory
https://twitter.com/floesen_/status/1337107178096881666	Third Party Advisory
https://twitter.com/the_secret_club/status/1380868759129296900	Exploit Third Party Advisory
https://www.youtube.com/watch?v=rNQn--9xR1Q	Exploit Third Party Advisory
https://news.ycombinator.com/item?id=26762170	Issue Tracking Third Party Advisory
https://twitter.com/floesen_/status/1337107178096881666	Third Party Advisory
https://twitter.com/the_secret_club/status/1380868759129296900	Exploit Third Party Advisory
https://www.youtube.com/watch?v=rNQn--9xR1Q	Exploit Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:valvesoftware:steam_client:*:*:*:*:*:*:*:*

History

03 Nov 2025, 06:15

Type	Values Removed	Values Added
Summary	(en) Valve Steam through 2021-04-10, when a Source engine game is installed, allows remote authenticated users to execute arbitrary code because of a buffer overflow that occurs for a Steam invite after one click.	(en) Valve Steam before 2021-04-17, when a Source engine game is installed, allows remote authenticated users to execute arbitrary code because of a buffer overflow that occurs for a Steam invite after one click.

Information

Published : 2021-04-10 19:15

Updated : 2025-11-03 06:15

NVD link : CVE-2021-30481

Mitre link : CVE-2021-30481

CVE.ORG link : CVE-2021-30481

JSON object : View

Products Affected

valvesoftware

steam_client

CWE

CWE-120

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

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