{"id":"CVE-2021-21375","aliases":["ALPINE-CVE-2021-21375","DEBIAN-CVE-2021-21375","DLA-2636-1","DLA-2665-1","EUVD-2021-8685","GHSA-hvq6-f89p-frvp","MGASA-2021-0336","MGASA-2021-0337","UBUNTU-CVE-2021-21375"],"status":"published","title":"Crash in receiving updated SDP answer after initial SDP negotiation failed","description":"PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In PJSIP version 2.10 and earlier, after an initial INVITE has been sent, when two 183 responses are received, with the first one causing negotiation failure, a crash will occur. This results in a denial of service.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0208,"percentile":0.81768,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-400","CWE-754"],"published":"2021-03-10T22:30:25Z","modified":"2026-10-23T18:03:48Z","fixes":[{"ecosystem":"Alpine:v3.14","package":"pjproject","fixed_in":["2.11-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.15","package":"pjproject","fixed_in":["2.11-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.16","package":"pjproject","fixed_in":["2.11-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.17","package":"pjproject","fixed_in":["2.11-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.18","package":"pjproject","fixed_in":["2.11-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.19","package":"pjproject","fixed_in":["2.11-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.20","package":"pjproject","fixed_in":["2.11-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.21","package":"pjproject","fixed_in":["2.11-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.22","package":"pjproject","fixed_in":["2.11-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.23","package":"pjproject","fixed_in":["2.11-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.24","package":"pjproject","fixed_in":["2.11-r0"],"sources":["osv"]},{"ecosystem":"Debian:12","package":"ring","fixed_in":["20210112.2.b757bac~ds1-1"],"sources":["osv"]},{"ecosystem":"Debian:9","package":"pjproject","fixed_in":["2.5.5~dfsg-6+deb9u2"],"sources":["osv"]},{"ecosystem":"Debian:9","package":"ring","fixed_in":["20161221.2.7bd7d91~dfsg1-1+deb9u1"],"sources":["osv"]},{"ecosystem":"Mageia:7","package":"pjproject","fixed_in":["2.7.2-1.1.mga7"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:16.04:LTS","package":"pjproject","fixed_in":["2.1.0.0.ast20130823-1+deb8u1ubuntu0.1~esm1"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:18.04:LTS","package":"pjproject","fixed_in":["2.7.2~dfsg-1ubuntu0.1~esm1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Alpine:v3.14","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.15","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.16","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.17","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.18","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.19","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.20","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.21","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.22","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.23","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.24","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.11-r0"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"ring","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"20210112.2.b757bac~ds1-1"}]}]},{"source":"osv","ecosystem":"Debian:9","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.5.5~dfsg-6+deb9u2"}]}],"versions":["2.5.5~dfsg-6","2.5.5~dfsg-6+deb9u1"]},{"source":"osv","ecosystem":"Debian:9","package":"ring","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"20161221.2.7bd7d91~dfsg1-1+deb9u1"}]}],"versions":["20161221.2.7bd7d91~dfsg1-1"]},{"source":"osv","ecosystem":"Mageia:7","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.7.2-1.1.mga7"}]}]},{"source":"osv","ecosystem":"Mageia:8","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.10-5.2.mga8"}]}],"bundled":2},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.1.0.0.ast20130823-1+deb8u1ubuntu0.1~esm1"}]}],"versions":["2.1.0.0.ast20130823-1","2.1.0.0.ast20130823-1+deb8u1build0.16.04.1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"pjproject","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.7.2~dfsg-1ubuntu0.1~esm1"}]}],"versions":["2.6~dfsg-2","2.7~dfsg-1","2.7.1~dfsg-1","2.7.1~dfsg-1build1","2.7.2~dfsg-1"]}],"products":[{"vendor":"debian","product":"debian_linux"},{"vendor":"pjsip","product":"pjproject"},{"vendor":"teluu","product":"pjsip"}],"references":[{"url":"https://github.com/pjsip/pjproject/security/advisories/GHSA-hvq6-f89p-frvp","tags":["x_refsource_CONFIRM","x_transferred","Exploit","Patch","Third Party Advisory","fix","advisory","report"]},{"url":"https://github.com/pjsip/pjproject/commit/97b3d7addbaa720b7ddb0af9bf6f3e443e664365","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","report"]},{"url":"https://lists.debian.org/debian-lts-announce/2021/04/msg00023.html","tags":["mailing-list","x_refsource_MLIST","x_transferred","Mailing List","Third Party Advisory","advisory"]},{"url":"https://lists.debian.org/debian-lts-announce/2021/05/msg00020.html","tags":["mailing-list","x_refsource_MLIST","x_transferred","Mailing List","Third Party Advisory","advisory"]},{"url":"https://security.gentoo.org/glsa/202107-42","tags":["vendor-advisory","x_refsource_GENTOO","x_transferred","Third Party Advisory","advisory"]},{"url":"https://security.alpinelinux.org/vuln/CVE-2021-21375","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-21375","tags":["advisory"]},{"url":"https://advisories.mageia.org/MGASA-2021-0336.html","tags":["advisory"]},{"url":"https://bugs.mageia.org/show_bug.cgi?id=28998","tags":["report"]},{"url":"https://www.debian.org/lts/security/2021/dla-2636","tags":["web"]},{"url":"https://advisories.mageia.org/MGASA-2021-0337.html","tags":["advisory"]},{"url":"https://github.com/pjsip/pjproject/security/advisories/GHSA-8hcp-hm38-mfph","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-21375","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-21375","tags":["report"]},{"url":"https://ubuntu.com/security/notices/USN-8122-1","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2021-21375","title":"Crash in receiving updated SDP answer after initial SDP negotiation failed","description":"PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In PJSIP version 2.10 and earlier, after an initial INVITE has been sent, when two 183 responses are received, with the first one causing negotiation failure, a crash will occur. This results in a denial of service.","status":"published","published":"2021-03-10T22:30:25Z","modified":"2024-08-03T18:09:15.916Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:32:59.802172Z"}],"euvd":[{"id":"EUVD-2021-8685","description":"PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In PJSIP version 2.10 and earlier, after an initial INVITE has been sent, when two 183 responses are received, with the first one causing negotiation failure, a crash will occur. This results in a denial of service.","status":"published","published":"2021-03-10T22:30:25Z","modified":"2024-08-03T18:09:15Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-03T03:25:06.347262Z"}],"nvd":[{"id":"CVE-2021-21375","description":"PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In PJSIP version 2.10 and earlier, after an initial INVITE has been sent, when two 183 responses are received, with the first one causing negotiation failure, a crash will occur. This results in a denial of service.","status":"published","published":"2021-03-10T23:15:12.52Z","modified":"2026-06-17T03:35:26.337Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"},{"version":"2.0","score":4.3,"vector":"AV:N/AC:M/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-400","CWE-754"],"updated_at":"2026-11-02T14:06:50.805771Z"}],"osv":[{"id":"ALPINE-CVE-2021-21375","description":"PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In PJSIP version 2.10 and earlier, after an initial INVITE has been sent, when two 183 responses are received, with the first one causing negotiation failure, a crash will occur. This results in a denial of service.","status":"published","published":"2021-03-10T23:15:12.52Z","modified":"2026-10-23T17:17:56.14809844Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:27:48.646074Z"},{"id":"CVE-2021-21375","description":"PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In PJSIP version 2.10 and earlier, after an initial INVITE has been sent, when two 183 responses are received, with the first one causing negotiation failure, a crash will occur. This results in a denial of service.","status":"published","published":"2021-03-10T23:15:12.52Z","modified":"2026-10-20T14:18:42.338996414Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:44:18.004149Z"},{"id":"DEBIAN-CVE-2021-21375","description":"PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In PJSIP version 2.10 and earlier, after an initial INVITE has been sent, when two 183 responses are received, with the first one causing negotiation failure, a crash will occur. This results in a denial of service.","status":"published","published":"2021-03-10T23:15:12.52Z","modified":"2026-10-23T18:03:48.670842947Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:45:34.637046Z"},{"id":"UBUNTU-CVE-2021-21375","description":"PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In PJSIP version 2.10 and earlier, after an initial INVITE has been sent, when two 183 responses are received, with the first one causing negotiation failure, a crash will occur. This results in a denial of service.","status":"published","published":"2021-03-10T23:15:00Z","modified":"2026-04-22T12:46:20.243616Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:54:26.29421Z"},{"id":"DLA-2636-1","title":"pjproject - security update","status":"published","published":"2021-04-23T00:00:00Z","modified":"2026-03-09T01:22:45.409664Z","updated_at":"2026-11-02T15:46:10.712745Z"},{"id":"DLA-2665-1","title":"ring - security update","status":"published","published":"2021-05-23T00:00:00Z","modified":"2026-03-09T01:21:25.875614Z","updated_at":"2026-11-02T15:46:10.712745Z"},{"id":"MGASA-2021-0336","title":"Updated pjproject packages fix a security vulnerability","description":"An issue has been found in pjproject. Due to bad handling of two consecutive\ncrafted answers to an INVITE, the attacker is able to crash the server\nresulting in a denial of service (CVE-2021-21375).\n","status":"published","published":"2021-07-10T20:00:34Z","modified":"2026-04-16T04:43:34.854009688Z","updated_at":"2026-11-02T15:49:41.509337Z"},{"id":"MGASA-2021-0337","title":"Updated pjproject packages fix security vulnerabilities","description":"Currently, PJSIP transport can be reused if they have the same IP address\n+ port + protocol. However, this is insufficient for secure transport since\nit lacks remote hostname authentication. The vulnerability allows for an\ninsecure interaction without user awareness. It affects users who need access\nto connections to different destinations that translate to the same address,\nand allows man-in-the-middle attack if attacker can route a connection to\nanother destination such as in the case of DNS spoofing (CVE-2020-15260).\n\nAn issue has been found in pjproject. Due to bad handling of two consecutive\ncrafted answers to an INVITE, the attacker is able to crash the server\nresulting in a denial of service (CVE-2021-21375).\n","status":"published","published":"2021-07-10T20:00:34Z","modified":"2026-04-16T04:44:14.20493981Z","updated_at":"2026-11-02T15:49:41.509337Z"}]}}