CVE-2013-1854 rubygem-activerecord: attribute_dos Symbol DoS vulnerability

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. A flaw was found in the way Ruby on Rails handled
hashes in certain queries. A remote attacker could use this flaw to perform a denial
of service (resource consumption) attack by sending specially crafted queries that
would result in the creation of Ruby symbols, which were never garbage collected.