Platform
ruby
Component
rails
Fixed in
2.3.3
CVE-2009-2422 is a critical authentication bypass vulnerability affecting Ruby on Rails versions 2.3.2 and earlier. The flaw resides within the example code for HTTP digest authentication, specifically the http_authentication.rb file. This allows attackers to potentially bypass authentication mechanisms in applications derived from this example by sending invalid usernames without passwords, leading to unauthorized access.
The primary impact of CVE-2009-2422 is unauthorized access to applications using the vulnerable digest authentication example. An attacker can bypass authentication by sending a request with an invalid username and no password. This is particularly concerning for applications that directly incorporate or adapt this example code without proper validation and error handling. The blast radius extends to any application relying on this flawed authentication logic, potentially exposing sensitive data and system resources. While the vulnerability is within an example, its inclusion in custom applications makes it a significant risk.
CVE-2009-2422 was publicly disclosed in 2017, although the vulnerability itself dates back to 2009. While no active exploitation campaigns have been widely reported, the vulnerability's severity and ease of exploitation make it a potential target. It is not currently listed on the CISA KEV catalog. Public proof-of-concept exploits are available, demonstrating the bypass technique.
Exploit Status
EPSS
0.40% (61% percentile)
CVSS Vector
The definitive mitigation for CVE-2009-2422 is to upgrade to Ruby on Rails version 2.3.3 or later, which contains the fix. If upgrading is not immediately feasible, carefully review and refactor any custom authentication logic derived from the http_authentication.rb example. Ensure that authentication failures are handled correctly, returning false instead of nil when a user does not exist. Consider implementing stricter input validation and error handling to prevent similar bypasses in the future. After upgrading, confirm the fix by attempting authentication with an invalid username and verifying that authentication fails as expected.
No official patch available. Check for workarounds or monitor for updates.
Vulnerability analysis and critical alerts directly to your inbox.
CVE-2009-2422 is a critical vulnerability in Ruby on Rails versions 2.3.2 and earlier where an attacker can bypass authentication by sending an invalid username without a password due to a flaw in the digest authentication example code.
You are affected if you are using Ruby on Rails version 2.3.2 or earlier, and your application uses or is derived from the HTTP digest authentication example code.
Upgrade to Ruby on Rails version 2.3.3 or later. If upgrading isn't possible, review and refactor any custom authentication logic derived from the vulnerable example code.
While no widespread active exploitation has been reported, the vulnerability's severity and ease of exploitation make it a potential target.
Refer to the Ruby on Rails security advisories and release notes for version 2.3.3 for details on the fix: https://github.com/rails/rails/releases/tag/v2.3.3
Upload your dependency file and we'll tell you instantly if this and other CVEs hit you.
Upload your Gemfile.lock file and we'll tell you instantly if you're affected.