{"id":"CVE-2021-26713","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-26713","generatedAt":"2026-10-27T21:17:01.961Z","title":"A stack-based buffer overflow in res_rtp_asterisk.c in Sangoma Asterisk before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6 allows an authenticated WebRTC client to cause an Asterisk crash by sending…","description":"A stack-based buffer overflow in res_rtp_asterisk.c in Sangoma Asterisk before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6 allows an authenticated WebRTC client to cause an Asterisk crash by sending multiple hold/unhold requests in quick succession. This is caused by a signedness comparison mismatch.","published":"2021-02-19T20:15:13.000Z","lastModified":"2026-06-17T03:43:42.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-787"],"affected":["digium/asterisk","digium/certified asterisk"],"epss":{"score":0.01868,"percentile":0.79178,"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":"low","text":"Lower severity and a low EPSS score (1.87%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://downloads.asterisk.org/pub/security/","tags":["Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://downloads.asterisk.org/pub/security/AST-2021-004.html","tags":["Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://issues.asterisk.org/jira/browse/ASTERISK-29205","tags":["Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://downloads.asterisk.org/pub/security/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://downloads.asterisk.org/pub/security/AST-2021-004.html","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://issues.asterisk.org/jira/browse/ASTERISK-29205","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-26713","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."}