Impact

In affected URI version, a bypass exists for the fix to CVE-2025-27221 that can expose user credentials.

When using the + operator to combine URIs, sensitive information like passwords from the original URI can be leaked, violating RFC3986 and making applications vulnerable to credential exposure.

The vulnerability affects the uri gem bundled with the following Ruby series:

0.12.4 and earlier (bundled in Ruby 3.2 series) 0.13.2 and earlier (bundled in Ruby 3.3 series) 1.0.3 and earlier (bundled in Ruby 3.4 series)

Patches

Upgrade to 0.12.5, 0.13.3 or 1.0.4

References

https://www.ruby-lang.org/en/news/2025/02/26/security-advisories/ https://hackerone.com/reports/2957667

In the URI gem before 1.0.3 for Ruby, the URI handling methods (URI.join, URI#merge, URI#+) have an inadvertent leakage of authentication credentials because userinfo is retained even after changing the host.

A ReDoS issue was discovered in the URI component before 0.12.2 for Ruby. The URI parser mishandles invalid URLs that have specific characters. There is an increase in execution time for parsing strings to URI objects with rfc2396parser.rb and rfc3986parser.rb.

NOTE: this issue exists becuse of an incomplete fix for CVE-2023-28755. Version 0.10.3 is also a fixed version.

The Ruby advisory recommends updating the uri gem to 0.12.2. In order to ensure compatibility with the bundled version in older Ruby series, you may update as follows instead: - For Ruby 3.0: Update to uri 0.10.3 - For Ruby 3.1 and 3.2: Update to uri 0.12.2.

You can use gem update uri to update it. If you are using bundler, please add gem uri, >= 0.12.2 (or other version mentioned above) to your Gemfile.