actionpack/lib/action_view/template/text.rb in Action View in Ruby on Rails 3.x before 3.2.17 converts MIME type strings to symbols during use of the :text…

actionpack/lib/action_view/template/text.rb in Action View in Ruby on Rails 3.x before 3.2.17 converts MIME type strings to symbols during use of the :text option to the render method, which allows remote attackers to cause a denial of service (memory consumption) by including these strings in headers.