CVE-2021-22903
6.1 · MEDIUMOverview
CVE-2021-22903 is a medium-severity vulnerability affecting rubyonrails rails. It was published on June 11, 2021 and has a CVSS 3.1 base score of 6.1 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 6.1, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
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 << "sub.example.com"` to permit a request with a Host header value of `sub-example.com`.
Remediation
Check the references section for vendor advisories and patches from rubyonrails. Update rails to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| rubyonrails | rails | >= 6.1.1, < 6.1.3.2 | Affected |
Frequently Asked Questions
What is CVE-2021-22903?
CVE-2021-22903 is a medium-severity vulnerability affecting rubyonrails rails. It was published on June 11, 2021 and has a CVSS 3.1 base score of 6.1 (MEDIUM).
How severe is CVE-2021-22903?
This vulnerability has a CVSS 3.1 base score of 6.1, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-22903?
Check the references section for vendor advisories and patches from rubyonrails. Update rails to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-22903?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-22903 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
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