{"id":"CVE-2021-30481","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-30481","generatedAt":"2026-10-27T22:24:47.715Z","title":"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.","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.","published":"2021-04-10T19:15:12.000Z","lastModified":"2026-06-17T03:50:19.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":9,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H"},"cwe":["CWE-120"],"affected":["valvesoftware/steam client"],"epss":{"score":0.03504,"percentile":0.89096,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (3.50%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://news.ycombinator.com/item?id=26762170","tags":["Issue Tracking","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://twitter.com/floesen_/status/1337107178096881666","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://twitter.com/the_secret_club/status/1380868759129296900","tags":["Exploit","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://www.youtube.com/watch?v=rNQn--9xR1Q","tags":["Exploit","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://news.ycombinator.com/item?id=26762170","tags":["Issue Tracking","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://twitter.com/floesen_/status/1337107178096881666","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://twitter.com/the_secret_club/status/1380868759129296900","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.youtube.com/watch?v=rNQn--9xR1Q","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-30481","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}