actionpack/lib/action_dispatch/http/request.rb in Ruby on Rails before 3.2.16 and 4.x before 4.0.2 does not properly consider differences in parameter handling between the Active Record component and the JSON implementation, which allows remote attackers to bypass intended database-query restrictions and perform NULL checks or trigger missing WHERE clauses via a crafted request that leverages (1) third-party Rack middleware or (2) custom Rack middleware. NOTE: this vulnerability exists because of an incomplete fix for CVE-2013-0155.

Cross-site scripting (XSS) vulnerability in the simple_format helper in actionpack/lib/action_view/helpers/text_helper.rb in Ruby on Rails 4.x before 4.0.2 allows remote attackers to inject arbitrary web script or HTML via a crafted HTML attribute.

Cross-site scripting (XSS) vulnerability in the number_to_currency helper in actionpack/lib/action_view/helpers/number_helper.rb in Ruby on Rails before 3.2.16 and 4.x before 4.0.2 allows remote attackers to inject arbitrary web script or HTML via the unit parameter.

actionpack/lib/action_view/lookup_context.rb in Action View in Ruby on Rails 3.x before 3.2.16 and 4.x before 4.0.2 allows remote attackers to cause a denial of service (memory consumption) via a header containing an invalid MIME type that leads to excessive caching.

Cross-site scripting (XSS) vulnerability in actionpack/lib/action_view/helpers/translation_helper.rb in the internationalization component in Ruby on Rails 3.x before 3.2.16 and 4.x before 4.0.2 allows remote attackers to inject arbitrary web script or HTML via a crafted string that triggers generation of a fallback string by the i18n gem.