My suggestion is to replace the existing web shell with Shell-in-a-box
http://www.htpcbeginner.com/increase-shellinabox-security/2
This would allow a full shell(vs the existing shell in QuickBox which is limited).
I can see the use for this when issuing sudo commands. If you look at the 2nd page of the 2nd link, it talks about using a reverse proxy and .htpasswd with it which would integrate well into Quickbox…for example only allowing it to be used by the master account.