Security problem in 3.83 ?
 

I'm using version 3.83 and my forums are at http://forums.watchuseek.com. Someone has managed to enter the forums and overload the database. One of my moderators received an e-mail twice in which he claims to slow down the forums. The forums were actually slowed down then and even put down causing a "database error" message on screen.

I decided to have all new registrations set to "Moderate New Members" and although some needs to be approved there are also new registrations that slip through without my approval.

Could this be a security problem in 3.83?