Public exploit details released on July 27 show how an unauthenticated request can reach PHP’s eval() function inside vBulletin and execute code on an unpatched forum server. The attack requires no account, administrative access, or interaction from another user.

SSD Secure Disclosure lists vBulletin 6.2.1 and earlier, and 6.1.6 and earlier, as affected, but does not give a lower version