[#1025] Fix Rails vulnerability (CVE-2012-2660)

config/initializers/10-patches.rb

@@ -115,4 +115,32 @@ module ActionController
       end
     end
   end
+
+  # Backported fix for CVE-2012-2660
+  # https://groups.google.com/group/rubyonrails-security/browse_thread/thread/f1203e3376acec0f
+  # TODO: Remove this once we are on Rails >= 3.2.4
+  require 'action_controller/request'
+  class Request
+    protected
+
+    # Remove nils from the params hash
+    def deep_munge(hash)
+      hash.each_value do |v|
+        case v
+        when Array
+          v.grep(Hash) { |x| deep_munge(x) }
+        when Hash
+          deep_munge(v)
+        end
+      end
+
+      keys = hash.keys.find_all { |k| hash[k] == [nil] }
+      keys.each { |k| hash[k] = nil }
+      hash
+    end
+
+    def parse_query(qs)
+      deep_munge(super)
+    end
+  end
 end