Evil code from the Python standard library [closed]

Question

So, we have had this: The 1000% Speedup, or, the stdlib sucks. It demonstrates a rather bad bug that is probably costing the universe a load of cycles even as we speak. It's fixed now, which is great.

So what parts of the standard library have you noticed to be evil?

I would expect all the responsible people to match up an answer with a bug report (if suitable) and a patch (if superman).

Answer 1

The rexec module has so many security holes in it that it's almost useless.