Quote:

" On 25 October 2012 we released a critical security patch for IP.Board to address an issue with PHP serialized data in the software. Today we are releasing an update that further enhances the security of the impacted areas. "

Full source + download:

Code: 
http://community.invisionpower.com/topic/372245-ipboard-33x-32x-and-31x-critical-security-update-6-november-2012/