See here an article on BBC about vBulletin forums and their vulnerabilities
BBC News - Firm scrambles to patch vBulletin software flaw
BBC News - Firm scrambles to patch vBulletin software flaw
I never said we have never been hacked I said we have not been effected by this latest exploit.
You live and learn, especially when you run your own servers.
They are never 100% safe, you just have to do what you can to minimize the risk.
The only 100% safe option, is to unplug them from the internet