Yes, it is possible, kind of since you will still need to give your users a username to use to log in to the FTP server.
Create a username (for example “Public”, or “Customer”, …), give access to the shares you want this user to have access to.
You have to turn on FTP in the NAS Dashboard.
Verify that your user can acces the NAS through FTP with a client like Filezilla or similar.
If the user works on your network, forward an external port (for example port 8021) to your NAS’s port 21.
You will need a DDNS service to give your router a public name and URL: [DDNSAddres}
You would then access the FTP servier through DDNSAddress:8021
http://community.wd.com/t5/WD-My-Cloud/FTP-access/m-p/614085#M921
