Metasploitable
One of the best ways to learn about exploits is to find a vulnerable system and attack it. Unfortunately, unless you own that system this approach is also very probably illegal. So don’t do that. You can craft your own vulnerable system. It’s pretty easy to get hold of a Windows XP virtual machine (and also perfectly legal – you can extract such a thing from XP Mode for Windows 7 installer at ) or an old Ubuntu ISO,
