How to prevent “aspxerrorpath” being passed as a query string to ASP.NET custom error pages

Question

In my ASP.NET web application, I have defined custom error pages in my web.config file as follows:

Answer 1

If you supply your own query string variable when specifying the path, then .NET will NOT tack on the "aspxerrorpath". Who knew?

For example:

This will do the trick. I had to add this to a bunch of apps since URLScan for IIS by default rejects anything with "aspxerrorpath" in it anyway.