{"cve":"CVE-2021-22881","nvd":{"published":"2021-02-11T18:15:17.460","modified":"2026-06-17T03:37:56.390","status":"Modified","description":"The Host Authorization middleware in Action Pack before 6.1.2.1, 6.0.3.5 suffers from an open redirect vulnerability. Specially crafted `Host` headers in combination with certain \"allowed host\" formats can cause the Host Authorization middleware in Action Pack to redirect users to a malicious website. Impacted applications will have allowed hosts with a leading dot. When an allowed host contains a leading dot, a specially crafted `Host` header can be used to redirect to a malicious website.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-601"],"references":["http://www.openwall.com/lists/oss-security/2021/05/05/2","http://www.openwall.com/lists/oss-security/2021/08/20/1","http://www.openwall.com/lists/oss-security/2021/12/14/5","https://benjamin-bouchet.com/cve-2021-22881-faille-de-securite-dans-le-middleware-hostauthorization/","https://discuss.rubyonrails.org/t/cve-2021-22881-possible-open-redirect-in-host-authorization-middleware/77130"],"products":["fedoraproject:fedora","rubyonrails:rails"],"source":"nvd","synced_at":"2026-10-19T21:14:10.479542811+00:00"},"epss":{"cve":"CVE-2021-22881","score":0.87301,"percentile":0.99753,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-8877-prq4-9xfw","url":"https://osv.dev/vulnerability/GHSA-8877-prq4-9xfw","summary":"Actionpack Open Redirect Vulnerability ","modified":"2024-02-20T05:32:38.542795Z","packages":[{"ecosystem":"RubyGems","name":"actionpack","purl":"pkg:gem/actionpack","ranges":[">=6.0.0 <6.0.3.5"],"fixed":["6.0.3.5"]},{"ecosystem":"RubyGems","name":"actionpack","purl":"pkg:gem/actionpack","ranges":[">=6.1.0 <6.1.2.1"],"fixed":["6.1.2.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}