request.rb in Web Console before 2.1.3, as used with Ruby on Rails 3.x and 4.x, does not properly restrict the use of X-Forwarded-For headers in determining a client's IP address, which allows remote attackers to bypass the whitelisted_ips protection mechanism via a crafted request.
https://groups.google.com/forum/message/raw?msg=rubyonrails-security/lzmz9_ijUFw/HBMPi4zp5NAJ
https://github.com/rails/web-console/blob/master/CHANGELOG.markdown
http://www.securityfocus.com/bid/75237
http://openwall.com/lists/oss-security/2015/06/16/18
http://lists.fedoraproject.org/pipermail/package-announce/2015-June/160881.html