CVE-2021-22903 Possible Open Redirect Vulnerability in Action Pack

What is CVE-2021-22903?

CVE-2021-22903 is a medium-severity vulnerability in Rubyonrails Rails, published on 11 Jun 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official 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`.

Weakness: CWE-601

Which versions are affected by CVE-2021-22903?

2 open source packages ship an affected version, including actionpack. It affects 1 product.

Products include Rubyonrails Rails.

How do I fix CVE-2021-22903?

Upgrade actionpack to 6.1.3.2 or later.

Is CVE-2021-22903 being exploited?

There is no known exploitation of CVE-2021-22903 in the wild and no public exploit code.

Other vulnerabilities in Rubyonrails Rails

• CVE-2013-0277 Active Record contains deserialization of arbitrary YAML Critical 10.0
• CVE-2017-17916 SQL injection in n/a High 8.1
• CVE-2017-17917 SQL injection in n/a High 8.1
• CVE-2026-33195 Rails Active Storage has possible Path Traversal in DiskService High 8.0
• CVE-2024-26142 Rails possible ReDoS vulnerability in Accept header parsing in Action Dispatch High 7.5

All Rubyonrails Rails vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-5hq2-xf89-9jxq, UBUNTU-CVE-2021-22903.