I am on a friends server and I have found a potential security flaw where I can access other sites files on the server. He says he is on a shared hosting and I am not sure yet if the other sites are his or not, he has to get back to me on that. In the meantime though I was wondering how do sites like godaddy deal with this issue? Do they put each account on the server into a sort of virtual server so you can access your other sites on your account but can not access sites on other accounts? It might be the case that his server is working properly and all the sites I can access are his sites anyway since they are under his account.
If they are all his sites then how can he prevent other sites from accessing other sites since some of them are for other peoples sites he manages for them.