{"id":"CVE-2021-31878","aliases":["EUVD-2021-18753","GHSA-h6p9-w9r4-7x73","UBUNTU-CVE-2021-31878"],"status":"published","title":"An issue was discovered in PJSIP in Asterisk before 16.19.1 and before 18.5.1. To exploit, a re...","description":"An issue was discovered in PJSIP in Asterisk before 16.19.1 and before 18.5.1. To exploit, a re-INVITE without SDP must be received after Asterisk has sent a BYE request.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-12","score":0.02463,"percentile":0.84695,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-617"],"published":"2021-07-27T05:17:05Z","modified":"2026-10-24T10:30:59Z","affected":[{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:13.1.0~dfsg-1.1ubuntu3","1:13.1.0~dfsg-1.1ubuntu4","1:13.1.0~dfsg-1.1ubuntu4.1","1:13.1.0~dfsg-1.1ubuntu4.1+esm1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:13.17.2~dfsg-1ubuntu1","1:13.17.2~dfsg-2ubuntu1","1:13.18.1~dfsg-1ubuntu1","1:13.18.3~dfsg-1ubuntu1","1:13.18.3~dfsg-1ubuntu2","1:13.18.3~dfsg-1ubuntu3","1:13.18.3~dfsg-1ubuntu4"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:16.2.1~dfsg-2build2","1:16.2.1~dfsg-2build3","1:16.2.1~dfsg-2ubuntu1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:16.16.1~dfsg-2","1:16.16.1~dfsg-4","1:16.16.1~dfsg-4build1","1:16.16.1~dfsg+~2.10-1","1:18.10.0~dfsg+~cs6.10.40431411-2"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:20.4.0~dfsg+~cs6.13.40431414-2","1:20.5.0~dfsg+~cs6.13.40431414-1","1:20.5.1~dfsg+~cs6.13.40431414-1","1:20.5.2~dfsg+~cs6.13.40431414-1","1:20.6.0~dfsg+~cs6.13.40431414-1","1:20.6.0~dfsg+~cs6.13.40431414-2","1:20.6.0~dfsg+~cs6.13.40431414-2build3","1:20.6.0~dfsg+~cs6.13.40431414-2build4","1:20.6.0~dfsg+~cs6.13.40431414-2build5"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:22.2.0~dfsg+~cs6.15.60671435-2","1:22.3.0~dfsg+~cs6.15.60671435-1","1:22.4.1~dfsg+~cs6.15.60671435-1","1:22.4.1~dfsg+~cs6.15.60671435-2","1:22.5.1~dfsg+~cs6.15.60671435-1","1:22.5.2~dfsg+~cs6.15.60671435-1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:22.5.2~dfsg+~cs6.15.60671435-1","1:22.10.0+dfsg+~cs6.17.60671434-1ubuntu2","1:22.10.0+dfsg+~cs6.17.60671434-1ubuntu3"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"asterisk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:22.5.2~dfsg+~cs6.15.60671435-1"]}],"products":[{"vendor":"digium","product":"asterisk"}],"references":[{"url":"http://seclists.org/fulldisclosure/2021/Jul/48","tags":["mailing-list","x_refsource_FULLDISC","x_transferred","Mailing List","Patch","Third Party Advisory","fix"]},{"url":"http://packetstormsecurity.com/files/163638/Asterisk-Project-Security-Advisory-AST-2021-007.html","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","VDB Entry","fix"]},{"url":"http://downloads.asterisk.org/pub/security/AST-2021-007.html","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory","fix","report"]},{"url":"https://issues.asterisk.org/jira/browse/ASTERISK-29381","tags":["x_refsource_MISC","x_transferred","Exploit","Issue Tracking","Vendor Advisory","report"]},{"url":"https://downloads.digium.com/pub/security/AST-2021-007.html","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-31878"},{"url":"https://github.com/advisories/GHSA-h6p9-w9r4-7x73"},{"url":"https://ubuntu.com/security/CVE-2021-31878","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-31878","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2021-31878","description":"An issue was discovered in PJSIP in Asterisk before 16.19.1 and before 18.5.1. To exploit, a re-INVITE without SDP must be received after Asterisk has sent a BYE request.","status":"published","published":"2021-07-27T05:17:05Z","modified":"2024-08-03T23:10:30.837Z","updated_at":"2026-11-02T14:33:05.665371Z"}],"euvd":[{"id":"EUVD-2021-18753","description":"An issue was discovered in PJSIP in Asterisk before 16.19.1 and before 18.5.1. To exploit, a re-INVITE without SDP must be received after Asterisk has sent a BYE request.","status":"published","published":"2021-07-27T05:17:05Z","modified":"2024-08-03T23:10:30Z","updated_at":"2026-11-03T03:24:37.97373Z"}],"ghsa":[{"id":"GHSA-h6p9-w9r4-7x73","title":"An issue was discovered in PJSIP in Asterisk before 16.19.1 and before 18.5.1. To exploit, a re...","description":"An issue was discovered in PJSIP in Asterisk before 16.19.1 and before 18.5.1. To exploit, a re-INVITE without SDP must be received after Asterisk has sent a BYE request.","status":"published","published":"2022-05-24T19:09:23Z","modified":"2023-01-30T05:01:11Z","cwes":["CWE-617"],"updated_at":"2026-11-02T14:46:21.093669Z"}],"nvd":[{"id":"CVE-2021-31878","description":"An issue was discovered in PJSIP in Asterisk before 16.19.1 and before 18.5.1. To exploit, a re-INVITE without SDP must be received after Asterisk has sent a BYE request.","status":"published","published":"2021-07-30T14:15:16.69Z","modified":"2026-06-17T03:52:23.84Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"},{"version":"2.0","score":4,"vector":"AV:N/AC:L/Au:S/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-617"],"updated_at":"2026-11-02T14:06:56.185362Z"}],"osv":[{"id":"CVE-2021-31878","description":"An issue was discovered in PJSIP in Asterisk before 16.19.1 and before 18.5.1. To exploit, a re-INVITE without SDP must be received after Asterisk has sent a BYE request.","status":"published","published":"2021-07-30T14:15:16.69Z","modified":"2026-10-24T10:30:59.200615139Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:44:19.483607Z"},{"id":"UBUNTU-CVE-2021-31878","description":"An issue was discovered in PJSIP in Asterisk before 16.19.1 and before 18.5.1. To exploit, a re-INVITE without SDP must be received after Asterisk has sent a BYE request.","status":"published","published":"2021-07-30T14:15:00Z","modified":"2026-10-17T12:56:15.22519913Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:54:27.332852Z"}]}}