COMMAND
MultiHTML
SYSTEMS AFFECTED
MultiHTML
PROBLEM
Niels Heinen found following. MultiHTML allows you to put an SSI
call where you want the HTML file to be displayed. The SSI
executes the MultiHTML program which displays whatever HTML file
you have it set to display. The main reason fpr posting this is
because of the fact that this script is offerd by many
lets-expand-our-cgi-bins-to-make-us-look-good isp's.
The cgi script checks the extentions of the requested file to see
if it is ok. This easily can be tricked by using %00 (Olaf Kirch)
http://localhost/cgi-bin/multihtml.pl?multi=/etc/passwd%00html
further their is no dcumentroot specified in the script so we do
not need to use the ../../ here because their is access to every
directory on the system in question (lame). Even if their was a
documentroot and they would filter the dots then you would have
to make sure that the script does not contain any higher
directory's. Because the open(FILE, "$multi") functions in the
script makes it easy to bypass .htaccess files.
SOLUTION
Be a man and learn how to use ssi without a script. Or beg
someone to write a new one.