Add the `Mime::Type::InvalidMimeType` error in the default rescue_response:

- https://github.com/rails/rails/pull/35604 introduced a vulnerability fix
  to raise an error in case the `HTTP_ACCEPT` headers contains malformated
  mime type.

  This will cause applications to throw a 500 if a User Agent sends an
  invalid header.

  This PR adds the `InvalidMimeType` in the default `rescue_responses` from
  the ExceptionWrapper and will return a 406. I looked up the HTTP/1.1
  RFC and it doesn't stand what should be returned when the UA
  sends malformated mime type. Decided to get 406 as it seemed to be the
  status the better suited for this.

3 files changed, 12 insertions, 3 deletions

diff --git a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
index 61773d97a2..bb49bc4dda 100644
--- a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
@@ -60,7 +60,11 @@ module ActionDispatch
         log_error(request, wrapper)
 
         if request.get_header("action_dispatch.show_detailed_exceptions")
-          content_type = request.formats.first
+          begin
+            content_type = request.formats.first
+          rescue Mime::Type::InvalidMimeType
+            render_for_api_request(Mime[:text], wrapper)
+          end
 
           if api_request?(content_type)
             render_for_api_request(content_type, wrapper)
diff --git a/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb b/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
index 1fb3e9db00..0cc56f5013 100644
--- a/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
+++ b/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
@@ -12,6 +12,7 @@ module ActionDispatch
       "ActionController::UnknownHttpMethod"          => :method_not_allowed,
       "ActionController::NotImplemented"             => :not_implemented,
       "ActionController::UnknownFormat"              => :not_acceptable,
+      "Mime::Type::InvalidMimeType"                  => :not_acceptable,
       "ActionController::MissingExactTemplate"       => :not_acceptable,
       "ActionController::InvalidAuthenticityToken"   => :unprocessable_entity,
       "ActionController::InvalidCrossOriginRequest"  => :unprocessable_entity,
diff --git a/actionpack/lib/action_dispatch/middleware/public_exceptions.rb b/actionpack/lib/action_dispatch/middleware/public_exceptions.rb
index 3feb3a19f3..a88ad40f21 100644
--- a/actionpack/lib/action_dispatch/middleware/public_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/public_exceptions.rb
@@ -21,8 +21,12 @@ module ActionDispatch
     def call(env)
       request      = ActionDispatch::Request.new(env)
       status       = request.path_info[1..-1].to_i
-      content_type = request.formats.first
-      body         = { status: status, error: Rack::Utils::HTTP_STATUS_CODES.fetch(status, Rack::Utils::HTTP_STATUS_CODES[500]) }
+      begin
+        content_type = request.formats.first
+      rescue Mime::Type::InvalidMimeType
+        content_type = Mime[:text]
+      end
+      body = { status: status, error: Rack::Utils::HTTP_STATUS_CODES.fetch(status, Rack::Utils::HTTP_STATUS_CODES[500]) }
 
       render(status, content_type, body)
     end