Get the Whitepaper called Changing Chmod Permissions / Traverse Base FTP / MultiHosting.
You can download it from the following link: https://packetstormsecurity.com/files/download/88909/changing-chmod.txt
Source: https://packetstormsecurity.com/files/88909/Whitepaper-Called-Changing-Chmod-Permissions-Traverse-Base-FTP-MultiHosting.html