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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2009-3086
• http://lists.opensuse.org/opensuse-security-announce/2009-10/msg00004.html
• http://weblog.rubyonrails.org/2009/9/4/timing-weakness-in-ruby-on-rails
• http://www.debian.org/security/2011/dsa-2260
• https://github.com/rubysec/ruby-advisory-db/blob/master/gems/actionpack/CVE-2009-3086.yml
• rails/rails@1f07a89
• rails/rails@674f780
• rails/rails@d460c9a
• https://web.archive.org/web/20090906010200/http://www.vupen.com/english/advisories/2009/2544
• https://web.archive.org/web/20090907001716/http://secunia.com/advisories/36600
• https://web.archive.org/web/20200229150042/http://www.securityfocus.com/bid/37427
• https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activesupport/CVE-2009-3086.yml