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CVE-2021-30481Valve Steam before 2021-04-17, when a Source engine game is installed, allows remote authenticated users to execute arbitrary code because…
- 8.0HighCVSS base score
- 3.5%Exploitation in 30 daysEPSS · top 11% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By mitre
Published
- 5 years later
· 5 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| mitreCNA (assigner) | 3.1 | High8.0 | CVSS:3.1/AC:H/AV:N/A:H/C:H/I:H/PR:L/S:C/UI:R |
| NVDNVD · Modified | 3.1 | Critical9.0 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 3.5% · top 11% of all CVEs (13 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.0.
Affected products
n/a
- affected n/a
References
References4
- https://twitter.com/the_secret_club/status/1380868759129296900 (opens in a new tab)x_refsource_MISCx_transferred
- https://www.youtube.com/watch?v=rNQn--9xR1Q (opens in a new tab)x_refsource_MISCx_transferred
- https://news.ycombinator.com/item?id=26762170 (opens in a new tab)x_refsource_MISCx_transferred
- https://twitter.com/floesen_/status/1337107178096881666 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-17404 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-30481)Record last updated .