CVE-2021-22881
URL Redirection to Untrusted Site
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.
Official description from the CVE record, published by hackerone. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
EPSS
- Score
- 0.87301 (87.3% probability)
- Percentile
- 99.8%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
Weakness (CWE)
- CWE-601URL Redirection to Untrusted Site
Affected products
https://github.com/rails/rails
- affected: Fixed in 6.1.2.1, 6.0.3.5
References
- hackerone.com/reports/1047447
- discuss.rubyonrails.org/t/cve-2021-22881-possible-open-redi…
- benjamin-bouchet.com/cve-2021-22881-faille-de-securite-dans…
- FEDORA-2021-b571fca1b8 (lists.fedoraproject.org)vendor-advisory
- [oss-security] 20210505 [CVE-2021-22903] Possible Open Redirect Vulnerability in Action Pack (openwall.com)mailing-list
- [oss-security] 20210819 [CVE-2021-22942] Possible Open Redirect in Host Authorization Middleware (openwall.com)mailing-list
- [oss-security] 20211214 [CVE-2021-44528] Possible Open Redirect in Host Authorization Middleware (openwall.com)mailing-list
Timeline
- ID reserved
- Record published
- Record last updated
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About CubePath
Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:53 UTC. Sources and licenses