I'm thinking of using Web Disk (built into the later versions of cPanel) to allow a Windows or Mac computer to map a network drive that is actually a folder on our website (above the public_html folder). We currently use an antiquated local server to store information, but it is only accessible from one location - we would like to be able to access it from other locations as well.

I understand that folders above public_html are not accessible via http, but I want to know how secure is the access to these folders as a network drive? There is potentially sensitive information that we need to decide whether it is appropriate to store here. The map network drive option seems to work well as it behaves as if the files are on your own computer (i.e. you can open and save files without then having to upload them - as it happens automatically).

We have used Dropbox for similar purposes, but space is a issue with them, as is accountability and so we haven't used it for sensitive information.

Are there any notable security concerns with using Web Disk as a secure file server?