Catch invalid UTF-8 querystring values and respond with BadRequest

2 files changed, 19 insertions, 1 deletions

diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index c6ab4dbc9a..35e3ac304f 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -338,7 +338,10 @@ module ActionDispatch
     # Override Rack's GET method to support indifferent access
     def GET
       fetch_header("action_dispatch.request.query_parameters") do |k|
-        set_header k, Request::Utils.normalize_encode_params(super || {})
+        rack_query_params = super || {}
+        # Check for non UTF-8 parameter values, which would cause errors later
+        Request::Utils.check_param_encoding(rack_query_params)
+        set_header k, Request::Utils.normalize_encode_params(rack_query_params)
       end
     rescue Rack::Utils::ParameterTypeError, Rack::Utils::InvalidParameterError => e
       raise ActionController::BadRequest.new("Invalid query parameters: #{e.message}", e)
diff --git a/actionpack/lib/action_dispatch/request/utils.rb b/actionpack/lib/action_dispatch/request/utils.rb
index a8151a8224..bb3df3c311 100644
--- a/actionpack/lib/action_dispatch/request/utils.rb
+++ b/actionpack/lib/action_dispatch/request/utils.rb
@@ -13,6 +13,21 @@ module ActionDispatch
         end
       end
 
+      def self.check_param_encoding(params)
+        case params
+        when Array
+          params.each { |element| check_param_encoding(element) }
+        when Hash
+          params.each_value { |value| check_param_encoding(value) }
+        when String
+          unless params.valid_encoding?
+            # Raise Rack::Utils::InvalidParameterError for consistency with Rack.
+            # ActionDispatch::Request#GET will re-raise as a BadRequest error.
+            raise Rack::Utils::InvalidParameterError, "Non UTF-8 value: #{params}"
+          end
+        end
+      end
+
       class ParamEncoder # :nodoc:
         # Convert nested Hash to HashWithIndifferentAccess.
         #