title: Why HttpRequestValidationException has 500 http error code instead of 400?
body: <p>When I tested my web-app based on MVC5 I found that <code>HttpRequestValidationException</code> returns 500 from <code>GetHttpCode()</code>.<br>
  I catch this exception during security testing of requests to the server. MVC performs request validation and throws this exception, I processed it in the <code>Application_Error</code> and got 500 code returned, but, in fact, if user passed wrong input to server I should return 400 error (bad request). so don't understand why the exception has 500 error. Where I am wrong ?</p>