CVE-2021-22881

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.

Predictions

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

References

• https://groups.google.com/g/rubyonrails-security/c/zN_3qA26l6E
• https://www.suse.com/security/cve/CVE-2021-22881.html
• https://nvd.nist.gov/vuln/detail/CVE-2021-22881
• https://github.com/rails/rails/commit/b5de7b3a4787d8a55aaad39f477c16e3af65e444
• https://hackerone.com/reports/1047447
• 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
• https://github.com/rails/rails
• https://github.com/rails/rails/blob/v6.1.2.1/actionpack/CHANGELOG.md
• https://github.com/rubysec/ruby-advisory-db/blob/master/gems/actionpack/CVE-2021-22881.yml
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XQ3NS4IBYE2I3MVMGAHFZBZBIZGHXHT3
• https://rubygems.org/gems/actionpack
• 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://security-tracker.debian.org/tracker/CVE-2021-22881