{"id":"CVE-2023-49786","summary":"Asterisk susceptible to Denial of Service via DTLS Hello packets during call initiation","details":"Asterisk is an open source private branch exchange and telephony toolkit. In Asterisk prior to versions 18.20.1, 20.5.1, and 21.0.1; as well as certified-asterisk prior to 18.9-cert6; Asterisk is susceptible to a DoS due to a race condition in the hello handshake phase of the DTLS protocol when handling DTLS-SRTP for media setup. This attack can be done continuously, thus denying new DTLS-SRTP encrypted calls during the attack. Abuse of this vulnerability may lead to a massive Denial of Service on vulnerable Asterisk servers for calls that rely on DTLS-SRTP. Commit d7d7764cb07c8a1872804321302ef93bf62cba05 contains a fix, which is part of versions 18.20.1, 20.5.1, 21.0.1, amd 18.9-cert6.","aliases":["GHSA-hxj9-xwr8-w8pq"],"modified":"2026-04-10T05:05:10.441366Z","published":"2023-12-14T19:47:46.306Z","database_specific":{"cwe_ids":["CWE-703"],"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/49xxx/CVE-2023-49786.json"},"references":[{"type":"WEB","url":"http://packetstormsecurity.com/files/176251/Asterisk-20.1.0-Denial-Of-Service.html"},{"type":"WEB","url":"http://seclists.org/fulldisclosure/2023/Dec/24"},{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2023/12/15/7"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2023/12/msg00019.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/49xxx/CVE-2023-49786.json"},{"type":"ADVISORY","url":"https://github.com/EnableSecurity/advisories/tree/master/ES2023-01-asterisk-dtls-hello-race"},{"type":"ADVISORY","url":"https://github.com/asterisk/asterisk/security/advisories/GHSA-hxj9-xwr8-w8pq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-49786"},{"type":"FIX","url":"https://github.com/asterisk/asterisk/commit/d7d7764cb07c8a1872804321302ef93bf62cba05"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/asterisk/asterisk","events":[{"introduced":"0"},{"fixed":"14d0e59f3d8f7521621561168ef4a297702d978f"},{"last_affected":"12da95e53ff42287ad69d6d5922e06c3d62010ac"},{"fixed":"35e0c6c0f4ec35493e9a4bb938226722ded35c61"}],"database_specific":{"versions":[{"introduced":"0"},{"fixed":"18.20.1"},{"last_affected":"= 21.0.0"},{"fixed":"18.9-cert6"}]}},{"type":"GIT","repo":"https://github.com/asterisk/asterisk","events":[{"introduced":"de4f63b4824c91a0cd9f3d95f3b7923bec71960c"},{"fixed":"f7a8ac086de697db30e376d589a6f4e17cfabef5"}],"database_specific":{"versions":[{"introduced":"19.0.0"},{"fixed":"20.5.1"}]}}],"versions":["18.17.0","18.17.0-rc1","18.17.1","18.18.0","18.18.0-rc1","18.18.1","18.19.0","18.19.0-rc1","18.19.0-rc2","18.20.0","18.20.0-rc1","18.9.0","18.9.0-rc1","21.0.0","21.0.0-pre1","21.0.0-rc1","certified-18.9-cert4","certified-18.9-cert5","certified/18.9-cert1","certified/18.9-cert1-rc1","certified/18.9-cert2","certified/18.9-cert3","certified/18.9-cert4"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-49786.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}