{"id":"CVE-2021-21439","aliases":["DEBIAN-CVE-2021-21439","DLA-3551-1","EUVD-2021-8713","GHSA-58p7-gj75-3437","UBUNTU-CVE-2021-21439"],"status":"published","title":"Possible DoS attack using a special crafted URL in email body","description":"DoS attack can be performed when an email contains specially designed URL in the body. It can lead to the high CPU usage and cause low quality of service, or in extreme case bring the system to a halt. This issue affects: OTRS AG ((OTRS)) Community Edition 6.0.x version 6.0.1 and later versions. OTRS AG OTRS 7.0.x version 7.0.26 and prior versions; 8.0.x version 8.0.13 and prior versions.","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":"2026-11-12","score":0.00877,"percentile":0.5949,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-754","CWE-755"],"published":"2021-06-14T07:55:10Z","modified":"2026-08-27T23:03:58Z","fixes":[{"ecosystem":"Debian:11","package":"otrs2","fixed_in":["6.0.32-5"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:11","package":"otrs2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.32-5"}]}],"versions":["2.0.4p01-10","2.0.4p01-11","2.0.4p01-12","2.0.4p01-13","2.0.4p01-14","2.0.4p01-14.1","2.0.4p01-15","2.0.4p01-16","2.0.4p01-17","2.0.4p01-18","2.0.4p01-6","2.0.4p01-7","2.0.4p01-8","2.0.4p01-9","2.0.99beta1-1","2.0.99beta1-2","2.1.1-1","2.1.3-1","2.1.4-1","2.1.4-2","2.1.5-1","2.1.5-2","2.1.5-3","2.1.6-1","2.1.7-1","2.1.7-2","2.2.0~beta2-1","2.2.0~beta3-1","2.2.1-1","2.2.2-1","2.2.3-1","2.2.4-1","2.2.5-1","2.2.5-2","2.2.6-1","2.2.7-1","2.2.7-2","2.2.7-2lenny1","2.2.7-2lenny2","2.2.7-2lenny3","2.2.7-3","2.3.2-1","2.3.2-2","2.3.3-1","2.3.4-1","2.3.4-2","2.3.4-3","2.3.4-4","2.3.4-5","2.3.4-6","2.3.4-7","2.4.10+dfsg1-1","2.4.10+dfsg1-2","2.4.10+dfsg1-3","2.4.5-1","2.4.5-2","2.4.5-3","2.4.5-4","2.4.5-5","2.4.6-1","2.4.6-2","2.4.7+dfsg1-1","2.4.7-1","2.4.7-2","2.4.7-3","2.4.7-4","2.4.7-5","2.4.7-6","2.4.8+dfsg1-1","2.4.9+dfsg1-1","2.4.9+dfsg1-2","2.4.9+dfsg1-3","2.4.9+dfsg1-3+squeeze1","2.4.9+dfsg1-3+squeeze3","2.4.9+dfsg1-3+squeeze4","2.4.9+dfsg1-3+squeeze5","2.4.9+dfsg1-4","2.4.9+dfsg1-5","3.0.10+dfsg1-1","3.0.10+dfsg1-2","3.0.11+dfsg1-1","3.0.8+dfsg1-1","3.0.9+dfsg1-1","3.1.0~beta4+dfsg1-1","3.1.0~beta5+dfsg1-1","3.1.0~rc1+dfsg1-1","3.1.1+dfsg1-1","3.1.1+dfsg1-2","3.1.10+dfsg1-1","3.1.11+dfsg1-1","3.1.12+dfsg1-1","3.1.12+dfsg1-2","3.1.12+dfsg1-3","3.1.2+dfsg1-1","3.1.2+dfsg1-2","3.1.2+dfsg1-3","3.1.3+dfsg1-1","3.1.3+dfsg1-2","3.1.4+dfsg1-1","3.1.5+dfsg1-1","3.1.5+dfsg1-2","3.1.5+dfsg1-3","3.1.6+dfsg1-1","3.1.7+dfsg1-1","3.1.7+dfsg1-2","3.1.7+dfsg1-3","3.1.7+dfsg1-4","3.1.7+dfsg1-5","3.1.7+dfsg1-6","3.1.7+dfsg1-7","3.1.7+dfsg1-8","3.1.8+dfsg1-1","3.1.9+dfsg1-1","3.2.1+dfsg1-1","3.2.10-1","3.2.10-2","3.2.11-1","3.2.11-1~bpo70+1","3.2.12-1","3.2.2+dfsg1-1","3.2.3+dfsg1-1","3.2.4-1","3.2.5-1","3.2.6-1","3.2.6-2","3.2.7-1","3.2.7-2","3.2.8-1","3.2.9-1","3.2.9-2","3.3.1-1","3.3.10-1","3.3.11-1","3.3.18-1~deb7u1","3.3.18-1~deb7u2","3.3.18-1~deb7u3","3.3.2-1","3.3.3-1","3.3.3-2","3.3.3-3","3.3.4-1","3.3.5-1","3.3.6-1","3.3.7-1","3.3.7-2","3.3.8-1","3.3.9-1","3.3.9-2","3.3.9-3","3.3.9-3~bpo70+1","4.0.10-1","4.0.11-1","4.0.12-1","4.0.13-1","4.0.13-1~bpo8+1","4.0.5-1","4.0.5-2","4.0.6-1","4.0.7-1","4.0.7-2","4.0.8-1","4.0.9-1","5.0.1-1","5.0.1-2","5.0.10-1","5.0.10-1~bpo8+1","5.0.11-1","5.0.12-1","5.0.13-1","5.0.13-1~bpo8+1","5.0.13-2","5.0.14-1","5.0.14-1~bpo8+1","5.0.15-1","5.0.16-1","5.0.16-1~bpo8+1","5.0.17-1","5.0.18-1","5.0.19-1","5.0.2-1","5.0.20-1","5.0.21-1","5.0.21-1~bpo9+1","5.0.22-1","5.0.23-1","5.0.23-1~bpo9+1","5.0.24-1","5.0.24-1~bpo9+1","5.0.3-1","5.0.5-1","5.0.6-1","5.0.6-1~bpo8+1","5.0.7-1","5.0.8+dfsg1-1","5.0.8-1","5.0.8-1~bpo8+1","5.0.9+dfsg1-1","5.0.9+repack1-1","6.0.1-1","6.0.10-1","6.0.11-1","6.0.11-1~bpo9+1","6.0.12-1","6.0.12-1~bpo9+1","6.0.13-1","6.0.14-1","6.0.15-1","6.0.16-1","6.0.16-2","6.0.17-1","6.0.18-1","6.0.19-1","6.0.2-1","6.0.20-1","6.0.20-1~bpo10+1","6.0.21-1","6.0.22-1","6.0.23-1","6.0.23-2","6.0.24-1","6.0.24-1~bpo10+1","6.0.25-1","6.0.25-2","6.0.25-3","6.0.25-3~bpo10+1","6.0.26-1","6.0.26-1~bpo10+1","6.0.27-1","6.0.27-1~bpo10+1","6.0.28-1","6.0.28-1~bpo10+1","6.0.28-2","6.0.29-1","6.0.29-1~bpo10+1","6.0.3-1","6.0.30-1","6.0.30-1~bpo10+1","6.0.30-2","6.0.32-1","6.0.32-2","6.0.32-2~bpo10+1","6.0.32-4","6.0.32-5~bpo10+1","6.0.4-1","6.0.5-1","6.0.6-1","6.0.7-1","6.0.8-1","6.0.8-1~bpo9+1","6.0.9-1","6.0.9-1~bpo9+1"]},{"source":"osv","ecosystem":"Debian:10","package":"otrs2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.16-2+deb10u1"}]}],"versions":["2.0.4p01-10","2.0.4p01-11","2.0.4p01-12","2.0.4p01-13","2.0.4p01-14","2.0.4p01-14.1","2.0.4p01-15","2.0.4p01-16","2.0.4p01-17","2.0.4p01-18","2.0.4p01-6","2.0.4p01-7","2.0.4p01-8","2.0.4p01-9","2.0.99beta1-1","2.0.99beta1-2","2.1.1-1","2.1.3-1","2.1.4-1","2.1.4-2","2.1.5-1","2.1.5-2","2.1.5-3","2.1.6-1","2.1.7-1","2.1.7-2","2.2.0~beta2-1","2.2.0~beta3-1","2.2.1-1","2.2.2-1","2.2.3-1","2.2.4-1","2.2.5-1","2.2.5-2","2.2.6-1","2.2.7-1","2.2.7-2","2.2.7-2lenny1","2.2.7-2lenny2","2.2.7-2lenny3","2.2.7-3","2.3.2-1","2.3.2-2","2.3.3-1","2.3.4-1","2.3.4-2","2.3.4-3","2.3.4-4","2.3.4-5","2.3.4-6","2.3.4-7","2.4.10+dfsg1-1","2.4.10+dfsg1-2","2.4.10+dfsg1-3","2.4.5-1","2.4.5-2","2.4.5-3","2.4.5-4","2.4.5-5","2.4.6-1","2.4.6-2","2.4.7+dfsg1-1","2.4.7-1","2.4.7-2","2.4.7-3","2.4.7-4","2.4.7-5","2.4.7-6","2.4.8+dfsg1-1","2.4.9+dfsg1-1","2.4.9+dfsg1-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ag","product":"((otrs)) community edition"},{"vendor":"otrs ag","product":"otrs"}],"references":[{"url":"https://otrs.com/release-notes/otrs-security-advisory-2021-09/","tags":["x_transferred","Vendor Advisory","advisory","report"]},{"url":"https://lists.debian.org/debian-lts-announce/2023/08/msg00040.html","tags":["mailing-list","x_transferred","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21439"},{"url":"https://github.com/advisories/GHSA-58p7-gj75-3437"},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-21439","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-21439","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-21439","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2021-21439","title":"Possible DoS attack using a special crafted URL in email body","description":"DoS attack can be performed when an email contains specially designed URL in the body. It can lead to the high CPU usage and cause low quality of service, or in extreme case bring the system to a halt. This issue affects: OTRS AG ((OTRS)) Community Edition 6.0.x version 6.0.1 and later versions. OTRS AG OTRS 7.0.x version 7.0.26 and prior versions; 8.0.x version 8.0.13 and prior versions.","status":"published","published":"2021-06-14T07:55:10.08Z","modified":"2024-09-16T19:52:22.948Z","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-754"],"updated_at":"2026-11-02T14:33:00.488332Z"}],"euvd":[{"id":"EUVD-2021-8713","description":"DoS attack can be performed when an email contains specially designed URL in the body. It can lead to the high CPU usage and cause low quality of service, or in extreme case bring the system to a halt. This issue affects: OTRS AG ((OTRS)) Community Edition 6.0.x version 6.0.1 and later versions. OTRS AG OTRS 7.0.x version 7.0.26 and prior versions; 8.0.x version 8.0.13 and prior versions.","status":"published","published":"2021-06-14T07:55:10Z","modified":"2024-09-16T19:52:22Z","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":"2026-11-03T00:55:19.119653Z"}],"ghsa":[{"id":"GHSA-58p7-gj75-3437","title":"DoS attack can be performed when an email contains specially designed URL in the body. It can...","description":"DoS attack can be performed when an email contains specially designed URL in the body. It can lead to the high CPU usage and cause low quality of service, or in extreme case bring the system to a halt. This issue affects: OTRS AG ((OTRS)) Community Edition 6.0.x version 6.0.1 and later versions. OTRS AG OTRS 7.0.x version 7.0.26 and prior versions; 8.0.x version 8.0.13 and prior versions.","status":"published","published":"2022-05-24T19:05:18Z","modified":"2023-09-08T05:03:21Z","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"}],"cwes":["CWE-754","CWE-755"],"updated_at":"2026-11-02T14:54:46.481792Z"}],"nvd":[{"id":"CVE-2021-21439","description":"DoS attack can be performed when an email contains specially designed URL in the body. It can lead to the high CPU usage and cause low quality of service, or in extreme case bring the system to a halt. This issue affects: OTRS AG ((OTRS)) Community Edition 6.0.x version 6.0.1 and later versions. OTRS AG OTRS 7.0.x version 7.0.26 and prior versions; 8.0.x version 8.0.13 and prior versions.","status":"published","published":"2021-06-14T08:15:10.097Z","modified":"2026-06-17T03:35:34.68Z","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-754","CWE-755"],"updated_at":"2026-11-02T14:06:54.892562Z"}],"osv":[{"id":"CVE-2021-21439","description":"DoS attack can be performed when an email contains specially designed URL in the body. It can lead to the high CPU usage and cause low quality of service, or in extreme case bring the system to a halt. This issue affects: OTRS AG ((OTRS)) Community Edition 6.0.x version 6.0.1 and later versions. OTRS AG OTRS 7.0.x version 7.0.26 and prior versions; 8.0.x version 8.0.13 and prior versions.","status":"published","published":"2021-06-14T08:15:10.097Z","modified":"2026-03-14T10:43:17.020389Z","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-2021-21439","description":"DoS attack can be performed when an email contains specially designed URL in the body. It can lead to the high CPU usage and cause low quality of service, or in extreme case bring the system to a halt. This issue affects: OTRS AG ((OTRS)) Community Edition 6.0.x version 6.0.1 and later versions. OTRS AG OTRS 7.0.x version 7.0.26 and prior versions; 8.0.x version 8.0.13 and prior versions.","status":"published","published":"2021-06-14T08:15:10.097Z","modified":"2026-08-27T23:03:58.902120447Z","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-2021-21439","description":"DoS attack can be performed when an email contains specially designed URL in the body. It can lead to the high CPU usage and cause low quality of service, or in extreme case bring the system to a halt. This issue affects: OTRS AG ((OTRS)) Community Edition 6.0.x version 6.0.1 and later versions. OTRS AG OTRS 7.0.x version 7.0.26 and prior versions; 8.0.x version 8.0.13 and prior versions.","status":"published","published":"2021-06-14T08:15:00Z","modified":"2025-10-24T04:50:07Z","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-3551-1","title":"otrs2 - security update","status":"published","published":"2023-08-31T00:00:00Z","modified":"2026-03-09T01:23:23.492308Z","updated_at":"2026-11-02T15:46:11.734021Z"}]}}