SEC Consult Vulnerability Lab Security Advisory < 20190821-0 > ======================================================================= title: Unauthenticated sensitive information leakage product: Zoho Corporation ManageEngine ServiceDesk Plus vulnerable version: v10 <10509 fixed version: v10 >=10509 CVE number: CVE-2019-15045, CVE-2019-15046 impact: Critical homepage: https://www.manageengine.com/products/service-desk/ found: 2019-06-27 by: Johannes Greil (Office Vienna) SEC Consult Vulnerability Lab An integrated part of SEC Consult Europe | Asia | North America https://www.sec-consult.com ======================================================================= Vendor description: ------------------- "ServiceDesk Plus is a game changer in turning IT teams from daily fire-fighting to delivering awesome customer service. It provides great visibility and central control in dealing with IT issues to ensure that businesses suffer no downtime. For 10 years and running, it has been delivering smiles to millions of IT folks, end users, and stakeholders alike." Source: https://www.manageengine.com/products/service-desk/ Business recommendation: ------------------------ The vendor provides a patched version and it should be installed immediately. Furthermore, a thorough security analysis is highly recommended as only a short spot check has been performed and further critical issues are to be expected. A workaround exists for mitigating vulnerability 1b (user enumeration). Vulnerability overview/description: ----------------------------------- 1) Unauthenticated sensitive information leakage a) Unauthenticated download of internal support ticket information (CVE-2019-15046) The software offers functionality (fosagent) that an unauthenticated attacker can exploit in order to gain information of internal "events". In our test it was possible to access sensitive internal information (tickets) written by users of this application in exchange with the support team. Depending on the contents of the tickets, sensitive data might leak through this functionality. It is likely, that it also depends on the configuration of ServiceDesk Plus which information is stored in those "events". b) User Enumeration in AjaxDomainServlet (CVE-2019-15045) It is possible to collect valid usernames by interacting with the "AjaxDomainServlet" function of the application without prior authentication. This vulnerability is useful to increase the efficiency of brute force attacks. If the username is known, it is easier to find the corresponding password. Furthermore, the servlet leaks information, whether the user is a locally configured or a domain user and it also leaks the internal domain names of the requested user account. According to the vendor, the affected feature is intended behaviour and a workaround in order to disable it has been provided (see further below). Proof of concept: ----------------- 1) Unauthenticated sensitive information leakage a) Unauthenticated download of internal support ticket information (CVE-2019-15046) The "fosagent" functionality provides a "download-file" servlet which an unauthenticated attacker can use in order to iterate through existing internal "events". The information that can be downloaded looks like internal ticket system information and other data exchanged between users and the help desk support team. It is necessary to supply the "log-pos" parameter given a number followed by a colon character and another number to access the corresponding event index. An attacker can just increment those numbers and access different information. https://$IP/fosagent/repl/download-file?log-pos=1:0 b) User Enumeration in AjaxDomainServlet (CVE-2019-15045) The following URL can be used to efficiently enumerate user accounts configured within ManageEngine ServiceDesk Plus. No prior authentication is required for this functionality. The "search" parameter is used for supplying the user account name. https://$IP/domainServlet/AJaxDomainServlet?action=searchLocalAuthDomain&search=$USER If the user exists and is a local user (configured within the web application) it will show "Not in Domain" as a result. If the user exists and is a domain user (e.g. LDAP) it will show the corresponding internal domain name as a result. If the page stays empty the user does not exist. Vulnerable / tested versions: ----------------------------- Version 10 has been tested. The vendor did not confirm whether older releases are affected as well. Vendor contact timeline: ------------------------ 2019-07-02: Contacting vendor through ManageEngine Security Response Center (MESRC) Uploaded security advisory to bugbounty.zoho.com 2019-07-02: Vendor: acknowledged our report and will get back to us soon 2019-07-08: Asking for a status update; reponse: "we've investigated the report and working on the fix now" 2019-07-10: Asking about CVE numbers and requesting heads-up before release 2019-08-13: Asking for a status update 2019-08-13: Vendor: vulnerability has already been fixed and released in version 10509 2019-08-21: Release of security advisory Solution: --------- The vendor provides an updated version which should be installed immediately. https://www.manageengine.com/products/service-desk/download.html The vendor also provided a link to their readme about the new release: https://www.manageengine.com/products/service-desk/readme.html#10509 Workaround: ----------- Vulnerability 1b - User Enumeration: the affected feature is intended behaviour for usability but the vendor provided a workaround in order to disable this feature. The admin can disable this in: Admin-Self-Service Portal Settings (Configuration - Allow Domain Filtering during Login). 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 J. Greil / @2019