CVE-2009-3086
A certain algorithm in Ruby on Rails 2.1.0 through 2.2.2, and 2.3.x before 2.3.4, leaks information about the complexity of message-digest signature verification in the cookie store, which might allow remote attackers to forge a digest via multiple attempts.
Date published : 2009-09-08
http://www.securityfocus.com/bid/37427
http://weblog.rubyonrails.org/2009/9/4/timing-weakness-in-ruby-on-rails