LimeSurvey 3.17.13 - Cross-Site Scripting

SEC Consult Vulnerability Lab Security Advisory < 20190912-0 >
=======================================================================
              title: Stored and reflected XSS vulnerabilities
            product: LimeSurvey
 vulnerable version: <= 3.17.13
      fixed version: =>3.17.14
         CVE number: CVE-2019-16172, CVE-2019-16173
             impact: medium
           homepage: https://www.limesurvey.org/
              found: 2019-08-23
                 by: Andreas Kolbeck (Office Munich)
                     David Haintz (Office Vienna)
                     SEC Consult Vulnerability Lab

                     An integrated part of SEC Consult
                     Europe | Asia | North America

                     https://www.sec-consult.com

=======================================================================

Vendor description:
-------------------
"LimeSurvey is the tool to use for your online surveys. Whether you are
conducting simple questionnaires with just a couple of questions or advanced
assessments with conditionals and quota management, LimeSurvey has got you
covered. LimeSurvey is 100% open source and will always be transparently developed.
We can help you reach your goals."

Source: https://www.limesurvey.org/


Business recommendation:
------------------------
LimeSurvey suffered from a vulnerability due to improper input
and output validation. By exploiting this vulnerability an attacker could:
    1. Attack other users of the web application with JavaScript code,
       browser exploits or Trojan horses, or
    2. perform unauthorized actions in the name of another logged-in user.

The vendor provides a patch which should be installed immediately.
Furthermore, a thorough security analysis is highly recommended as only a
short spot check has been performed and additional issues are to be expected.


Vulnerability overview/description:
-----------------------------------
1) Stored and reflected XSS vulnerabilities
LimeSurvey suffers from a stored and reflected cross-site scripting vulnerability,
which allows an attacker to execute JavaScript code with the permissions of the victim.
In this way it is possible to escalate privileges from a low-privileged account e.g.
to "SuperAdmin".


Proof of concept:
-----------------
1) Stored and reflected XSS vulnerabilities
Example 1 - Stored XSS (CVE-2019-16172):
The attacker needs the appropriate permissions in order to create new survey groups.
Then create a survey group with a JavaScript payload in the title, for example:

test<svg/onload=alert(document.cookie)>

When the survey group is being deleted, e.g. by an administrative user, the JavaScript
code will be executed as part of the "success" message.


Example 2 - Reflected XSS (CVE-2019-16173):
The following proof of concept prints the current CSRF token cookie which contains the
CSRF token. The parameter "surveyid" is not filtered properly:

http://$host/index.php/admin/survey?mandatory=1&sid=xxx&surveyid=xxx%22%3E%3Cimg%20
src=x%20onerror=%22alert(document.cookie)%22%3E&sa=listquestions&sort=question


If the URL schema is configured differently the following payload works:
http://$host/index.php?r=admin/survey&mandatory=1&sid=xxx&surveyid=
xxx"><img%20src=x%20onerror="alert(document.cookie)">&sa=listquestions&sort=question


Vulnerable / tested versions:
-----------------------------
The vulnerabilities have been verified to exist in version 3.17.9 and the latest
version 3.17.13. It is assumed that older versions are affected as well.


Vendor contact timeline:
------------------------
2019-08-29: Contacting vendor through https://bugs.limesurvey.org/view.php?id=15204
2019-09-02: Fixes available:
            https://github.com/LimeSurvey/LimeSurvey/commit/32d6a5224327b246ee3a2a08500544e4f80f9a9a
            https://github.com/LimeSurvey/LimeSurvey/commit/f1c1ad2d24eb262363511fcca2e96ce737064006
2019-09-02: Release of LimeSurvey v3.17.14 which fixes the security issues
2019-09-03: Release of LimeSurvey v3.17.15 bug fix
2019-09-12: Coordinated release of security advisory


Solution:
---------
Update to version 3.17.15 or higher:
https://www.limesurvey.org/stable-release

The vendor provides a detailed list of changes here:
https://www.limesurvey.org/limesurvey-updates/2188-limesurvey-3-17-14-build-190902-released


Workaround:
-----------
No workaround available.


Advisory URL:
-------------
https://www.sec-consult.com/en/vulnerability-lab/advisories/index.html


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

SEC Consult Vulnerability Lab

SEC Consult
Europe | Asia | North America

About SEC Consult Vulnerability Lab
The SEC Consult Vulnerability Lab is an integrated part of SEC Consult. It
ensures the continued knowledge gain of SEC Consult in the field of network
and application security to stay ahead of the attacker. The SEC Consult
Vulnerability Lab supports high-quality penetration testing and the evaluation
of new offensive and defensive technologies for our customers. Hence our
customers obtain the most current information about vulnerabilities and valid
recommendation about the risk profile of new technologies.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Interested to work with the experts of SEC Consult?
Send us your application https://www.sec-consult.com/en/career/index.html

Interested in improving your cyber security with the experts of SEC Consult?
Contact our local offices https://www.sec-consult.com/en/contact/index.html
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Mail: research at sec-consult dot com
Web: https://www.sec-consult.com
Blog: http://blog.sec-consult.com
Twitter: https://twitter.com/sec_consult

EOF A. Kolbeck / @2019