Here is my 2 cents.
I think sooner or later no matter what flavor of classic or ubb it is, there will come a day someone will find a way to exploit the software.
Now in defense of classic we used to have a lot of hacks at ubbdev.
I recall one was a captcha hack where it was a question answer method.
But you can't seem to find help for many of those old hacks now.
Also there are things that are recommended in the classic manual to mitigate security issues. Like moving the member files above the root. Email validation and moderated registrations.
But it seems very few people with a problem follow those recommendations.
I do know ubb threads 6.x has a security risk in one of the scripts.
I believe it is "addpost_newpoll.php".
