eval()
will allow malicious data to compromise your entire system, kill your cat, eat your dog and make love to your wife.
There was recently a thread about how to do this kind of thing safely on the python-dev list, and the conclusions were:
- It’s really hard to do this properly.
- It requires patches to the python interpreter to block many classes of attacks.
- Don’t do it unless you really want to.
Start here to read about the challenge: http://tav.espians.com/a-challenge-to-break-python-security.html
What situation do you want to use eval() in? Are you wanting a user to be able to execute arbitrary expressions? Or are you wanting to transfer data in some way? Perhaps it’s possible to lock down the input in some way.