adv.txt

adv.txt (text/plain), 7.80 KB, created by Peter Volkov (RETIRED) on 2008-09-29 07:43:04 UTC

Mantis Bug Tracker 1.1.1 Multiple Vulnerabilities
 
 Name              Multiple Vulnerabilities in Mantis
 Systems Affected  Mantis 1.1.1 and possibly earlier versions
 Severity          High
 Impact (CVSSv2)   High 9/10, vector: (AV:N/AC:L/Au:N/C:C/I:P/A:P)
 Vendor            http://www.mantisbt.org/
 Advisory          http://www.ush.it/team/ush/hack-mantis111/adv.txt
 Authors           Antonio "s4tan" Parata (s4tan AT ush DOT it)
                   Francesco "ascii" Ongaro (ascii AT ush DOT it)
 Date
 
I. BACKGROUND
 
From the Mantis web site: "Mantis is a free popular web-based
bug tracking system. It is written in the PHP scripting language and
works with MySQL, MS SQL, and PostgreSQL databases and a webserver.".
 
II. DESCRIPTION
 
Multiple vulnerabilities exist in Mantis software (XSS, CSRF, Remote
Code Execution).
 
III. ANALYSIS
 
Summary:
 A) XSS Vulnerabilities
    return_dynamic_filters.php (filter_target parameter)
 B) CSRF Vulnerabilities
    manage_user_create.php
 C) Remote Code Execution Vulnerabilities
    adm_config_set.php (value parameter)
 
A) XSS Vulnerabilities
 
We have found an XSS vulnerability in return_dynamic_filters.php. In
order to exploit this vulnerability the attacker must be authenticated.
Usually the anonymous user is allowed on typical installation, so the
impact is a bit higher. The following url is a proof of concept:
 
http://www.example.com/mantis/return_dynamic_filters.php?filter_target=
<script>alert(document.cookie);</script>
 
B) CSRF Vulnerabilities
 
There is a Cross Site Request Forgery vulnerability in the software. If a
logged in user with administrator privileges clicks on the following url:
 
http://www.example.com/mantis/manage_user_create.php?username=foo&realn
ame=aa&password=aa&password_verify=aa&email=[e-mail]&access_lev
el=90&protected=0&enabled=1
 
a new user 'foo' with administrator privileges is created. The password
of the new user is sent to [e-mail].
 
C) Remote Code Execution Vulnerabilities
 
Finally we present the most critical vulnerability. A Remote Code
Execution vulnerability exists in the software, but it can be exploited
only if the attacker has a valid administrator account, so it could be
ideal if used in conjunction with the previous one. The vulnerability 
is in the file adm_config_set.php. On row 80 we have the following 
statement:
 
eval( '$t_value = ' . $f_value . ';' );
 
where the $f_value is defined at row 34 of the same file:
 
$f_value = gpc_get_string( 'value' );
 
the parameter $f_value is never validated, so we can exploit this issue
with the following url which executes the phpinfo() function:
 
http://www.example.com/mantis/adm_config_set.php?user_id=0&project_id=0
&config_option=cache_config&type=0&value=0;phpinfo()
 
IV. DETECTION
 
Mantis 1.1.1 and possibly earlier versions are vulnerable.
 
V. WORKAROUND
 
Proper input validation will fix the vulnerabilities.
 
Upgrade to latest development version 1.2.0a1.
 
VI. VENDOR RESPONSE
 
It was a little surprise to find out that somebody issued CVE-2008-2276
during our responsible disclosure time-line.
 
From an internal email with Glenn Henshaw:
 
--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--
 
# 8974 : XSS Vulnerability in filters - fixed for 1.1.2
# 8977 : Port 0008974: XSS Vulnerability in filters - fixed for 1.2.0
         and future
         - this issue has been fixed by escaping the data in the error
         message.
# 8976 : Remote Code Execution in adm_config - workaround in place in
         1.1.2
         - this page is only accessible to registered administrators
# 8980 : Port: Remote Code Execution in adm_config - workaround in
         place in 1.2.0 and beyond
         - this page is only accessible to registered administrators
# 8975 : CSRF Vulnerabilities in user_create
# 8995 : Port: CSRF Vulnerabilities in user_create
         - this has been fixed by ensuring that action pages can only
         be accessed via POST commands.
 
--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--
 
So "CSRF Vulnerabilities in user_create" is an our finding. The vendor
fixed by allowing only POST parameters that is obviously a non-fix.
 
Our response:
 
--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--
 
This alone isn't enough since forms can be auto-submitted by js that 
are irrespective of the same-orgin policy.
 
Proper remediation should include referer checking (has proved to be
spoofable on the client side in the past so not a bulletproof 
technique) and token checking (a random string or an hash generated 
when the user requires the frontend, stored serverside - sessions are 
okay -, included in the frontend form and sent to and verified by the 
backend).
 
These two protections ensure that an action cannot, hopefully, be 
CSRFed (at last in absence of an xss vuln that neutralize the same 
origin policy again).
 
--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--
 
Glenn response:
 
--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--
 
Thanks for the notice. The CSRF patch for rev 1.1.2 is in place using 
just a "POST" check. I have added a more sophisticated token based 
check to rev 1.2.0 (the patch is attached for review). I should be 
submitting this shortly.
 
--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--
 
Glenn final update about the patch not being incorporated upstream:
 
--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--
 
As a final update on this subject, the status of these issues has not 
changed. The token based CSRF implementation was rejected by the 
development team, and will not be implemented (at least by me). The 
consensus was that it was too complex to resolve a "rare" problem. 
 
--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--8<--
 
Since responsible disclosure didn't worked well with this vendor and
turned out to be very resource expensive we will publish future issues
affecting this product directly to independent security researchers, 
developers and users.
 
The wrong attribution of CVE-2008-2276 before our official advisory
strengthen our conviction that responsible disclosure isn't always 
fair.
 
We discussed long with Glenn Henshaw about issues and how to fix them
in mantis and we didn't expect to find a CVE credited to one of our 
interlocutors. He was surely aware of who was deserving credits and 
should have taken proper steps to prevent or fix this.
 
VII. CVE INFORMATION
 
No CVE at this time.
 
VIII. DISCLOSURE TIMELINE
 
20080121 Bug discovered
20080213 Vendor contacted
         -- LONG VENDOR SLOWNESS --
20080512 Last vendor mail about development and compatibility issues
20080515 CVE-2008-2276 wrongly credited to Glenn Henshaw (thraxisp)
20080520 Advisory released (forced disclosure)
 
IX. CREDIT
 
Antonio "s4tan" Parata and Francesco "ascii" Ongaro are credited with
the discovery of this vulnerability.
 
Antonio "s4tan" Parata
web site: http://www.ictsc.it/
mail: s4tan AT ictsc DOT it, s4tan AT ush DOT it
 
Francesco "ascii" Ongaro
web site: http://www.ush.it/
mail: ascii AT ush DOT it
 
X. LEGAL NOTICES
 
Copyright (c) 2007 Francesco "ascii" Ongaro
 
Permission is granted for the redistribution of this alert
electronically. It may not be edited in any way without mine express
written consent. If you wish to reprint the whole or any
part of this alert in any other medium other than electronically, 
please email me for permission.
 
Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct, indirect,
or consequential loss or damage arising from use of, or reliance on,
this information.