> > In my mind only one issue remains - when we say "we will serve files from directory X", how
> > to we prevent mhttpd from serving files outside this directory by using trick URLs containing ".."
> > and/or other gimmicks.
> > 
> > Disallow multi-level URL path names (by rejecting names that contain the directory separator "/").
> > Replace the URL check "/ is not permitted" with ".. is not permitted".
>
> https://en.wikipedia.org/wiki/Directory_traversal_attack

and, from Mitre's "Common Weakness Enumeration", with examples:

http://cwe.mitre.org/data/definitions/22.html

K.O.