Mantis Bug Tracker 1.1.1 Multiple Vulnerabilities

`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 20080520  
  
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 protected]&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 [email protected].  
  
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.  
  
nUE0p QbiY3q3ql55o3I0 qJWy YzAioF9 3LKEwnQ92 CIEhqzkE L0kIMy9S  
  
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.  
  
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