Ruby on Rails Improper Authentication Vulnerability - CVE-2012-3424

The decode_credentials method in actionpack/lib/action_controller/metal/http_authentication.rb in Ruby on Rails 3.x before 3.0.16 3.1.x before 3.1.7 and 3.2.x before 3.2.7 converts Digest Authentication strings to symbols which allows remote attackers to cause a denial of service by leveraging access to an application that uses a with_http_digest helper method as demonstrated by the authenticate_or_request_with_http_digest method.