Details here.
These are 4 simple text edits you can do in notepad.
I would also recommend that everyone using the software periodically download your database to secure your data. All of the popular blog software has been hacked or spam exploited so I guess it's a testament to the popularity of the software.
Here's the exploit details but I don't really understand how an "advisory site" with only one exploit listed, could've heard about this only minutes after the hacks occurred. Hmmm...it looks like they're the ones who did the hacking but I'll reserve judgment until this simple coincidence is explained to me. Where did they get the info for this hack? Was it sent to them or did they write it?
Hopefully all of the people using bp blog can get a backup of their database from their server admin of their host from yesterday. It's always good to have some sort of backup, even if that's just downloading your database every couple of days.