Launchpad.net

CVE 2013-1854

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.

See the CVE page on Mitre.org for more details.