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