Our new NAS has a web admin that isn't WAN accessible. Is there a way to access it through our WAN-accessible staging server, which is on the same lan as the NAS? Could I mount the NAS web root as a virtual host on the other server?

You're looking for a "Reverse Proxy" - almost certainly doable :)

I can think of a few reasons why it wouldn't work. It accesses services on the host is number 1. Maybe a vnc -type solution could work, dunno if the NAS supports it though.

Cool. I'll check it out.

An SSH Socks proxy would work as well.

Possibly even better.

That's usually how I access browser based stuff on my local network from outside.

Looks a good deal more secure, but I guess I need to get a port opened for it.

Yeah, obscure port, maybe some security through obscurity with a relatively complex password (or shared ssh key).

If it's a Linux system that has other user accounts it's possible to restrict logins on those accounts to certain IP ranges (LAN IP range). Leaving only your "secure" account for outside access.