{"schemaVersion":3,"id":"CVE-2021-22902","aliases":["UBUNTU-CVE-2021-22902","DEBIAN-CVE-2021-22902","GHSA-g8ww-46x2-2p65"],"status":"published","duplicateOf":null,"title":null,"description":"The actionpack ruby gem (a framework for handling and responding to web requests in Rails) before 6.0.3.7, 6.1.3.2 suffers from a possible denial of service vulnerability in the Mime type parser of Action Dispatch. Carefully crafted Accept headers can cause the mime type parser in Action Dispatch to do catastrophic backtracking in the regular expression engine.","dates":{"published":"2021-06-11T15:49:38.000Z","modified":"2024-08-03T18:58:25.713Z","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:N/A:H","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:N/A:H","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:N/A:H","exploitability":10,"impact":6,"computed":true},{"version":"3.1","versionLabel":"v3.1","source":"OSV · Rubygems","score":7.5,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","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:N/A:H","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:N/A:P","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.02868,"percentile":0.86594,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":0.07699999999999999,"baselineDate":"2026-09-19T00:00:00.000Z","baselineScore":0.02791},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.02868,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.02868,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.02868,"percentile":0.86594}],"last30":[{"date":"2026-09-19T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.02791,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.02868,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.02868,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.02868,"percentile":0.86594}]},"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_819BC1527993B847","name":"Exploit Reference (discuss.rubyonrails.org)","source":"reference","url":"https://discuss.rubyonrails.org/t/cve-2021-22902-possible-denial-of-service-vulnerability-in-action-dispatch/77866","maturity":"unknown","reliabilityScore":0.2,"verified":false,"type":null,"platforms":[],"requiresAuth":null,"exploitdb":null,"metasploit":null}],"exploitCount":1,"weaknesses":[{"id":"CWE-400","name":"Uncontrolled Resource Consumption","description":"The product does not properly control the allocation and maintenance of a limited resource.","type":"weakness","status":"Draft","abstraction":"Class","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/400.html"}],"affected":[{"vendor":"debian","product":"rails","name":"rails","label":"rails","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/rails","purlType":"deb","versions":[{"text":"< 2:6.0.3.7+dfsg-1","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 2:6.0.3.7+dfsg-1","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"rails","name":"rails","label":"rails","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/rails","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"RubyGems","product":"actionpack","name":"actionpack","label":"actionpack","ecosystem":"RubyGems","cpePart":null,"purl":"pkg:gem/actionpack","purlType":"gem","versions":[{"text":"≥ 6.0.0, < 6.0.3.7","noFixRecorded":false,"fixedIn":null},{"text":"≥ 6.1.0, < 6.1.3.2","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 6.0.0, < 6.0.3.7 | ≥ 6.1.0, < 6.1.3.2","eol":null,"hubHref":null},{"vendor":"rubyonrails","product":"rails","name":"rails","label":"rails","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 6.0.0, < 6.0.3.7","noFixRecorded":false,"fixedIn":null},{"text":"≥ 6.1.0, < 6.1.0.2","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 6.0.0, < 6.0.3.7 | ≥ 6.1.0, < 6.1.0.2","eol":{"isEol":null,"eolDate":null,"matchMethod":"cpe","cycle":null,"product":{"name":"rails","label":"Ruby on Rails","category":"framework"}},"hubHref":"/vendor/rubyonrails/rails"}],"affectedCount":4,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://hackerone.com/reports/1138654","label":"hackerone.com/reports/1138654","hostname":"hackerone.com","tags":["X Refsource MISC","WEB","Permissions Required","Third Party Advisory"]},{"url":"https://discuss.rubyonrails.org/t/cve-2021-22902-possible-denial-of-service-vulnerability-in-action-dispatch/77866","label":"discuss.rubyonrails.org/t/…","hostname":"discuss.rubyonrails.org","tags":["X Refsource MISC","WEB","Exploit","Mitigation","Patch","Vendor Advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-22902","label":"ubuntu.com/security/CVE-2021-22902","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-22902","label":"www.cve.org/CVERecord?id=CVE-2021-22902","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-22902","label":"security-tracker.debian.org/tracker/CVE-2021-22902","hostname":"security-tracker.debian.org","tags":["Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-22902","label":"nvd.nist.gov/vuln/detail/CVE-2021-22902","hostname":"nvd.nist.gov","tags":["Advisory"]},{"url":"https://github.com/rails/rails/releases/tag/v6.0.3.7","label":"github.com/rails/rails/releases/tag/v6.0.3.7","hostname":"github.com","tags":["WEB"]},{"url":"https://github.com/rails/rails/releases/tag/v6.1.3.2","label":"github.com/rails/rails/releases/tag/v6.1.3.2","hostname":"github.com","tags":["WEB"]},{"url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/actionpack/CVE-2021-22902.yml","label":"github.com/rubysec/ruby-advisory-db/blob/master/gems/actionpack/CVE-2021-22902.yml","hostname":"github.com","tags":["WEB"]},{"url":"https://groups.google.com/g/rubyonrails-security/c/_5ID_ld9u1c","label":"groups.google.com/g/rubyonrails-security/c/_5ID_ld9u1c","hostname":"groups.google.com","tags":["WEB"]}],"lineage":{"upstream":[],"downstream":["OPENSUSE-SU-2024:11821-1","RHSA-2021:4702"],"duplicates":[],"related":["OPENSUSE-SU-2024:11821-1"]},"timeline":[{"kind":"published","date":"2021-06-11T15:49:38.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2024-08-03T18:58:25.713Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":41,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-20T13:34:42.844Z","stale":false,"partial":false}}