J.A. Gutierrez found following.   WWW HTTP/1.0 Server, as  shipped
 with  IRIX  6.2  (at  least  in  low end machines) includes a perl
 script (wrap) which allows anyone on the net to get a listing  for
 any directory with mode +755.

 Simply use:

    http://sgi.victim/cgi-bin/wrap?/../../../../../etc