{"schemaVersion":3,"id":"CVE-2021-45098","aliases":["UBUNTU-CVE-2021-45098","DEBIAN-CVE-2021-45098"],"status":"published","duplicateOf":null,"title":null,"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.","dates":{"published":"2021-12-16T04:07:57.000Z","modified":"2025-11-03T19:26:34.251Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":7.5,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"NVD","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"OSV · Ubuntu","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","exploitability":10,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Debian","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","exploitability":10,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","exploitability":null,"impact":null,"computed":false},{"version":"2.0","versionLabel":"v2.0","source":"NVD","score":5,"severity":"medium","vector":"AV:N/AC:L/Au:N/C:N/I:P/A:N","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.01961,"percentile":0.80137,"severity":"low","asOf":"2026-10-21T00:00:00.000Z","change":{"pp":0.13699999999999996,"baselineDate":"2026-09-21T00:00:00.000Z","baselineScore":0.01824},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.01961,"percentile":0.80137}],"last30":[{"date":"2026-09-21T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.01824,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.01961,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.01961,"percentile":0.80137}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[{"id":"REF_2717BD419BED85EF","name":"Exploit Reference (redmine.openinfosecfoundation.org)","source":"reference","url":"https://redmine.openinfosecfoundation.org/issues/4710","maturity":"unknown","reliabilityScore":0.2,"verified":false,"type":null,"platforms":[],"requiresAuth":null,"exploitdb":null,"metasploit":null}],"exploitCount":1,"weaknesses":[],"affected":[{"vendor":"debian","product":"suricata","name":"suricata","label":"suricata","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/suricata","purlType":"deb","versions":[{"text":"< 1:6.0.4-1","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 1:6.0.4-1","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"suricata","name":"suricata","label":"suricata","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/suricata","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"debian","product":"debian_linux","name":"debian linux","label":"debian_linux","ecosystem":null,"cpePart":"o","purl":null,"purlType":null,"versions":[{"text":"9.0","noFixRecorded":false,"fixedIn":null},{"text":"10.0","noFixRecorded":false,"fixedIn":null},{"text":"11.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"9.0 | 10.0 | 11.0","eol":{"isEol":true,"eolDate":"2022-07-01T00:00:00.000Z","matchMethod":"cpe","cycle":{"name":"9","label":"9 (Stretch)","eolFrom":"2022-07-01T00:00:00.000Z","isLts":false,"isMaintained":true,"latestVersion":"9.13"},"product":{"name":"debian","label":"Debian","category":"os"}},"hubHref":"/vendor/debian/debian_linux"},{"vendor":"oisf","product":"suricata","name":"suricata","label":"suricata","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"< 6.0.4","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 6.0.4","eol":null,"hubHref":"/vendor/oisf/suricata"}],"affectedCount":4,"eol":{"hasEol":true,"count":1},"references":[{"url":"https://github.com/OISF/suricata/releases","label":"github.com/OISF/suricata/releases","hostname":"github.com","tags":["X Refsource MISC","REPORT","Release Notes","Third Party Advisory"]},{"url":"https://redmine.openinfosecfoundation.org/issues/4710","label":"redmine.openinfosecfoundation.org/issues/4710","hostname":"redmine.openinfosecfoundation.org","tags":["X Refsource MISC","REPORT","Exploit","Issue Tracking","Patch","Vendor Advisory"]},{"url":"https://forum.suricata.io/t/suricata-6-0-4-and-5-0-8-released/1942","label":"forum.suricata.io/t/suricata-6-0-4-and-5-0-8-released/1942","hostname":"forum.suricata.io","tags":["X Refsource MISC","REPORT","Release Notes","Vendor Advisory"]},{"url":"https://github.com/OISF/suricata/commit/50e2b973eeec7172991bf8f544ab06fb782b97df","label":"github.com/OISF/suricata/commit/50e2b973eeec7172991bf8f544ab06fb782b97df","hostname":"github.com","tags":["X Refsource MISC","REPORT","Patch","Third Party Advisory"]},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00029.html","label":"lists.debian.org/debian-lts-announce/2025/03/msg00029.html","hostname":"lists.debian.org","tags":[]},{"url":"https://ubuntu.com/security/CVE-2021-45098","label":"ubuntu.com/security/CVE-2021-45098","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-45098","label":"www.cve.org/CVERecord?id=CVE-2021-45098","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-45098","label":"security-tracker.debian.org/tracker/CVE-2021-45098","hostname":"security-tracker.debian.org","tags":["Advisory"]}],"lineage":{"upstream":[],"downstream":["DLA-4103-1"],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2021-12-16T04:07:57.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2025-11-03T19:26:34.251Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":40,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-22T08:31:39.708Z","stale":false,"partial":false}}