Handle Custom error on asp mvc 5 when potentially dangerous occurred - asp.net

Question

I've got the following error when I have : in url address:
A potentially dangerous Request.Path value was detected from the client (:)
I want when my application get an error I can redirect to /Error/NotFound action but sometimes it doesn't happen.
For example, I have below code for handle custom errors and it works properly but when I have a potentially dangerous error controller.Execute() doesn't fire.
protected void Application_Error()
{
var lastException = Server.GetLastError();
if (lastException.GetType() != typeof(HttpException))
return;
var httpException = lastException as HttpException;
var routeData = new RouteData();
routeData.Values.Add("controller", "Error");
if (httpException?.GetHttpCode() == 404 || httpException?.GetHttpCode() == 400)
routeData.Values.Add("action", "NotFound");
if (routeData.Values.Count <= 1)
return;
try
{
IController controller = new ErrorController();
controller.Execute(new RequestContext(new HttpContextWrapper(Context), routeData));
}
catch (NullReferenceException e)
{
Console.WriteLine(e.Message);
throw new NullReferenceException();
}
}
I realize that when a potentially dangerous error occurred some property of my context such as CurrentNotification, Handler, Items, Profile, Session and User is null. I don't know exactly my context is related to this problem or not.
And here is my webconfig:
<system.web>
<compilation debug="true" targetFramework="4.6.2" />
<httpRuntime targetFramework="4.6.2" maxRequestLength="314572800" enableVersionHeader="false" requestPathInvalidCharacters="<,>,%,&,:,\,?" />
</system.web>
<system.webServer>
<httpErrors errorMode="Custom" existingResponse="Replace">
<remove statusCode="404" />
<error statusCode="404" responseMode="ExecuteURL" path="/Error/NotFound" />
</httpErrors>
</system.webServer>

Answer 1

you can handle all types of errors in your Web.Config like this :
<customErrors mode="On" defaultRedirect="~/Error/ErrorPage/404" >
<error statusCode="404" redirect="~/Error/ErrorPage/404" />
<error statusCode="403" redirect="~/Error/ErrorPage/403" />
<error statusCode="500" redirect="~/Error/ErrorPage/500" />
</customErrors>
what i added is the
defaultRedirect
to handle any type of errors