{"id":"CVE-2021-22903","details":"The actionpack ruby gem before 6.1.3.2 suffers from a possible 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. This is similar to CVE-2021-22881. Strings in config.hosts that do not have a leading dot are converted to regular expressions without proper escaping. This causes, for example, `config.hosts \u003c\u003c \"sub.example.com\"` to permit a request with a Host header value of `sub-example.com`.","aliases":["GHSA-5hq2-xf89-9jxq"],"modified":"2026-04-10T04:30:15.410907Z","published":"2021-06-11T16:15:11.437Z","references":[{"type":"REPORT","url":"https://hackerone.com/reports/1148025"},{"type":"FIX","url":"https://discuss.rubyonrails.org/t/cve-2021-22903-possible-open-redirect-vulnerability-in-action-pack/77867"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/rails/rails","events":[{"introduced":"5f3ff60084ab5d5921ca3499814e4697f8350ee7"},{"fixed":"75ac626c4e21129d8296d4206a1960563cc3d4aa"},{"introduced":"0"},{"last_affected":"b38eb45ad9cb2041b30ac5d4d7b5b6e7b911ff2e"}],"database_specific":{"versions":[{"introduced":"6.1.1"},{"fixed":"6.1.3.2"},{"introduced":"0"},{"last_affected":"6.1.0-rc2"}]}}],"versions":["v0.10.0","v0.10.1","v0.11.0","v0.11.1","v0.12.0","v0.13.0","v0.13.1","v0.14.1","v0.14.3","v0.9.1","v0.9.2","v0.9.3","v0.9.4","v0.9.4.1","v0.9.5","v1.1.0","v1.1.0_RC1","v1.1.1","v2.0.0","v2.0.0_PR","v2.0.0_RC1","v2.0.0_RC2","v2.0.1","v3.0.0.beta.3","v3.0.0.beta3","v3.1.0.beta1","v3.1.0.rc1","v3.2.0.rc1","v4.0.0.beta1","v4.0.0.rc1","v4.2.0.beta1","v5.0.0.beta1","v5.0.0.beta2","v5.0.0.beta4","v5.1.0.beta1","v6.0.0.beta1","v6.0.0.beta2","v6.1.0.rc1","v6.1.0.rc2","v6.1.1","v6.1.2","v6.1.3","v6.1.3.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-22903.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"}]}