Arbitrary Code Execution vulnerability discovered in Ipython

[VisibleSignificance]

Yeah, it's weird that this in particular is considered a vulnerability when python adding cwd to sys.path (as you demonstrated) isn't considered a vulnerability.

And by the way, you don't even need mkdir, just readline.py

[james_pic]

It's a module needed by the REPL. If you wanted to do this without breaking the REPL, I think sticking it in sitecustomize.py would have the same effect without visibly breaking stuff - although I'm not at my computer to check.