The Active Record component in Ruby on Rails 2.3.x before 2.3.18, 3.1.x before 3.1.12, and 3.2.x before 3.2.13 processes certain queries by converting hash keys to symbols, which allows remote attackers to cause a denial of service via crafted input to a where method.
https://github.com/advisories/GHSA-3crr-9vmg-864v
https://groups.google.com/group/ruby-security-ann/msg/34e0d780b04308de?dmode=source&output=gplain
http://weblog.rubyonrails.org/2013/3/18/SEC-ANN-Rails-3-2-13-3-1-12-and-2-3-18-have-been-released/
http://support.apple.com/kb/HT5784
http://rhn.redhat.com/errata/RHSA-2014-1863.html
http://rhn.redhat.com/errata/RHSA-2013-0699.html
http://lists.opensuse.org/opensuse-updates/2013-04/msg00079.html
http://lists.opensuse.org/opensuse-updates/2013-04/msg00078.html
http://lists.opensuse.org/opensuse-updates/2013-04/msg00075.html
http://lists.opensuse.org/opensuse-updates/2013-04/msg00071.html
http://lists.opensuse.org/opensuse-updates/2013-04/msg00070.html
http://lists.apple.com/archives/security-announce/2013/Oct/msg00006.html
http://lists.apple.com/archives/security-announce/2013/Jun/msg00000.html