Minor bug in Pagelog.cgi

[Mark Stratman <mstrat1 () UIC EDU>]

There is a small bug in PAGELOG.cgi by Metertek (Metertek () yahoo com) which
allows users to create and view files.

Any file on the system with a '.log' extension readable by the uid/gid of
the webserver can be viewed. In addition, two files with extensions of
'.txt' and '.log' can be created in any directory on the system that is
writable by the web server.
This bug lies in the failure of the script to check for directory
traversal.

Proofs of concept:
Viewing '.log' file:
        Create a file 'a.log' in tmp.
        http://server/cgi-bin/pagelog.cgi?display=../../../../tmp/a
        This will let you view a.log
Creating files:
        http://server/cgi-bin/pagelog.cgi?name=../../../../../tmp/blah
        This will create blah.txt and blah.log in /tmp/


The script can be found at http://members.nbci.com/metertek/archive/


cheers.
Mark Stratman (count0)
(mstrat1 () uic edu)
http://sporkstorms.org