You can find it on the menus (which are now aligned by the PTES and OSSTMM standards) under CMS Identification:
|BackTrack -> Information Gathering -> Web Application Analysis -> CMS Identification -> cms-explorer|
|If you see this message, you need to add your API key.|
|Put your OSVDB API Key in the $osvdb_api_key variable.|
Thanks to the BackTrack team for continuing to enhance the pentesting distro and adding new tools like this (and others)!