I was testing a new proxy server today with SSL Labs and found that I had somehow included some anonymous cipher suites.
After resolving the problem I decided to find out what problems this could cause and how/why this was exploitable. To my surprise (considering the report and rating cap from SSL Labs) I was unable to find out much more then its possible to perform a MiTM, where weak ciphers are used.
Obviously I'm not looking for a how to, rather an explanation as to why it is exploitable and what would/could happen if these cipher suites had been left in place? Or is the answer it allows for a MiTM to take place?