{"id":"CVE-2021-45098","aliases":["ALPINE-CVE-2021-45098","DEBIAN-CVE-2021-45098","DLA-4103-1","EUVD-2021-31889","GHSA-cfcf-x7x2-gpf8","UBUNTU-CVE-2021-45098"],"status":"published","title":"An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based...","description":"An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.01961,"percentile":0.80586,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"published":"2021-12-16T04:07:57Z","modified":"2026-11-03T06:32:41Z","fixes":[{"ecosystem":"Alpine:v3.15","package":"suricata","fixed_in":["6.0.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.16","package":"suricata","fixed_in":["6.0.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.17","package":"suricata","fixed_in":["6.0.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.18","package":"suricata","fixed_in":["6.0.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.19","package":"suricata","fixed_in":["6.0.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.20","package":"suricata","fixed_in":["6.0.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.21","package":"suricata","fixed_in":["6.0.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.22","package":"suricata","fixed_in":["6.0.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.23","package":"suricata","fixed_in":["6.0.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.24","package":"suricata","fixed_in":["6.0.4-r0"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"suricata","fixed_in":["1:6.0.4-1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"suricata","fixed_in":["1:6.0.4-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Alpine:v3.15","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.16","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.17","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.18","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.19","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.20","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.21","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.22","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.23","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.24","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.4-r0"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:6.0.4-1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:6.0.4-1"}]}]},{"source":"osv","ecosystem":"Debian:11","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:6.0.1-3+deb11u1"}]}],"versions":["1:6.0.1-3"],"bundled":7},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.8-1build1","2.0.9-1","2.0.10-1","2.0.10-2","2.0.11-1","3.0-1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"suricata","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.2-2ubuntu3"]}],"products":[{"vendor":"debian","product":"debian_linux"},{"vendor":"oisf","product":"suricata"}],"references":[{"url":"https://github.com/OISF/suricata/releases","tags":["x_refsource_MISC","x_transferred","Release Notes","Third Party Advisory","advisory","report"]},{"url":"https://redmine.openinfosecfoundation.org/issues/4710","tags":["x_refsource_MISC","x_transferred","Exploit","Issue Tracking","Patch","Vendor Advisory","fix","report"]},{"url":"https://forum.suricata.io/t/suricata-6-0-4-and-5-0-8-released/1942","tags":["x_refsource_MISC","x_transferred","Release Notes","Vendor Advisory","advisory","report"]},{"url":"https://github.com/OISF/suricata/commit/50e2b973eeec7172991bf8f544ab06fb782b97df","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","report"]},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00029.html","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-45098"},{"url":"https://github.com/advisories/GHSA-cfcf-x7x2-gpf8"},{"url":"https://security.alpinelinux.org/vuln/CVE-2021-45098","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-45098","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-45098","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-45098","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2021-45098","description":"An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.","status":"published","published":"2021-12-16T04:07:57Z","modified":"2025-11-03T19:26:34.251Z","updated_at":"2026-11-02T14:33:02.580561Z"}],"euvd":[{"id":"EUVD-2021-31889","description":"An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.","status":"published","published":"2021-12-16T04:07:57Z","modified":"2025-11-03T19:26:34Z","updated_at":"2026-11-02T19:49:34.152725Z"}],"ghsa":[{"id":"GHSA-cfcf-x7x2-gpf8","title":"An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based...","description":"An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.","status":"published","published":"2021-12-17T00:00:32Z","modified":"2025-11-03T21:30:37Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T15:04:18.176646Z"}],"nvd":[{"id":"CVE-2021-45098","description":"An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.","status":"published","published":"2021-12-16T05:15:08.727Z","modified":"2026-06-17T04:13:10.223Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"updated_at":"2026-11-02T14:07:02.566991Z"}],"osv":[{"id":"ALPINE-CVE-2021-45098","description":"An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.","status":"published","published":"2021-12-16T05:15:08.727Z","modified":"2026-11-03T06:32:41.605735324Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-03T07:17:02.90744Z"},{"id":"CVE-2021-45098","description":"An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.","status":"published","published":"2021-12-16T05:15:08.727Z","modified":"2026-10-20T14:06:55.761317129Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T15:44:21.877444Z"},{"id":"DEBIAN-CVE-2021-45098","description":"An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.","status":"published","published":"2021-12-16T05:15:08.727Z","modified":"2026-10-23T18:05:06.616278597Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T15:45:35.799676Z"},{"id":"UBUNTU-CVE-2021-45098","description":"An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.","status":"published","published":"2021-12-16T05:15:00Z","modified":"2025-10-24T04:50:38Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T15:54:30.277322Z"},{"id":"DLA-4103-1","title":"suricata - security update","status":"published","published":"2025-03-31T00:00:00Z","modified":"2026-03-09T01:18:14.108597Z","updated_at":"2026-11-02T15:46:12.7027Z"}]}}