sorry i've only ever used phpbb forums...but to let you know the security issue is because you were using an older version of phpbb
the latest version of 2 is phpBB 2.0.21
they're working on version 3 it's in beta 3.0.4 at the moment and it's a hell of a lot better than any previous versions...they're finally starting (i say starting, still needs work but gettin there) to catch up with VB and IPB forums

[edit] well and since phpbb is open source there will always be potential for security issues...but keepin up to date on versions helps eliminate some of those risks