This is a copy of the original question on Stack Overflow which didn't get much love and is probably more relevant here:
There are plenty of performance reasons why apps shouldn't be run in debug="true" mode (good rundown from Scott Gu), but are there any attack vectors exposed by this practice? It's not a question of "should you or shouldn't you", that much is clear, it's a question of whether it introduces any specific vulnerabilities.
I'm inclined to think that the ability to remotely detect it combined with the known performance issues could lead to an exploit against service availability but I'd like something a bit more definite. Does anyone know of a specific attack that can be orchestrated against an app running debug="true"?