I recently received uploads from ip address 127.0.0.1. And that's quite impossible because that's the local ip address of the server. So I'm wondering if there is a bug or is there an exploit for the script?
Don't think it's a hack. We use HTTP_X_FORWARDED_FOR header to get IP if available (allow to get ip behind the proxy) - I guess this dude just use local proxy on his computer.
If you would like to use standard method you can find in Session.pm