Open Redirect in Rubyonrails Rails
CVE-2021-22881
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.
Vulnerability class: Open Redirect
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.873 (99.8th percentile), scored .
High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.873 · newest: 0.873 · change: 0.000
Affected products
- Rubyonrails Rails
- Fedoraproject Fedora — versions 33
- Https://github.com/rails/rails — versions Fixed in 6.1.2.1, 6.0.3.5
Weakness classification (CWE)
Public proof-of-concept exploits
References
- hackerone.com/reports/1047447 (Exploit, Patch, Third Party Advisory)
- discuss.rubyonrails.org/t/cve-2021-22881-possible-open-redirect-in-host-authori… (Patch, Mitigation, Vendor Advisory)
- benjamin-bouchet.com/cve-2021-22881-faille-de-securite-dans-le-middleware-hosta… (Patch, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- www.openwall.com/lists/oss-security/2021/05/05/2 (mailing-list, Mailing List, Third Party Advisory, Mitigation)
- www.openwall.com/lists/oss-security/2021/08/20/1 (mailing-list, Mailing List, Third Party Advisory, Mitigation)
- www.openwall.com/lists/oss-security/2021/12/14/5 (mailing-list, Exploit, Patch, Mailing List)
Frequently asked questions
- What is CVE-2021-22881?
- CVE-2021-22881 is a medium-severity vulnerability in Rubyonrails Rails, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2021-02-11.
- How severe is CVE-2021-22881?
- Medium severity. CVSS v3 base score is 6.1 out of 10.
- Is CVE-2021-22881 known to be exploited?
- 5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.