ManageEngine ServiceDesk Plus 9.0 – Authentication Bypass
Title: ManageEngine ServiceDesk Plus Application Compromise Date: 19 May 2017 Researcher: Steven Lackey (ByteM3) Product: ServiceDesk Plus (http://www.manageengine.com/) Affected Version: 9.0 (Other versions could also be affected) Fixed Version: Service Pack 9241 – Build 9.2 Vulnerability Impact: High Published Date: Email: bytem3 [at] bytem3.com <http://cyberdefensetechnologies.com/> Product Introduction =============== ServiceDesk Plus is ITIL-ready help desk software with integrated Assetand Project Management capabilities. With advanced ITSM functionality and easy-to-use capability, ServiceDesk Plus helps IT support teams deliver world-class service to end users with reduced costs and complexity. It comes in three editions and is available in 29 different languages. Over 100,000 organizations, across 185 countries, trust ServiceDesk Plus to optimize IT service desk performance and achieve high end user satisfaction. Source: https://www.manageengine.com/products/service-desk/ Vulnerability Information ================== Class: Backdoor Impact: Account and Application Compromise Remotely Exploitable: Yes Authentication Required: Yes User interaction required: Yes CVE Name: N/A Vulnerability Description =================== A valid username can be used as both username/password to login and compromise the application through the “/mc/” directory which is the ‘mobile client’ directory. This can be achieved ONLY if Active Directory/LDAP is being used. This flaw exists because of the lack of password randomization in the application version 9.0 when a user is entered into the application, thus the application assigns the password as the username. The flaw can then be exploited by logging into the application through the “/mc” directory and then backing out of the “/mc” directory by deleting it from the URL thus positioning you in the main application with the authority of the user you logged in as. (Help locating a valid username can come from another discovered vulnerability in this same version of software here: https://www.exploit-db.com/exploits/35891/ - with credit to Muhammad Ahmed Siddiqui for discovering how to enumerate usernames) Proof-of-Concept Authenticated User ============================ An attacker can use the following URL to login to the mobile client with any workstation: http://server/mc/ Use the discovered username in both the username and password fields. Ensure the “Is AD Auth” box is checked and click login. Once logged in, remove “/mc/” from the URL and you will be presented with the full application and the authorities of the user you just logged in with. You can now continue to look for usernames inside the application until a user with administrative privileges has been discovered and can compromise with administrative authority. Please note, ServiceDesk Plus has the ability to ‘scan’ machines on any available network it can see, meaning, system accounts are typically entered into the application to keep an inventory of machines that ServiceDesk can manage. It is possible to compromise not only the hosting machine for this application, however, the entire network as I did on the Penetration Test where I discovered this ‘backdoor’. Vendor Response ======= I have contacted the vendor and they advised they have fixed this particular issue with a new service pack ‘9241’, however, this insanely vulnerability is still out there, as this scenario has not been published as of yet, other than the vendors statement on their 9.2 Release readme webpage (https://www.manageengine.com/products/service-desk/readme-9.2.html) and email to me here: “FIX: PATCH *SD-61664 :* Based on Database configuration, an option to set the LocalAuthentication password as Random or predefined, for the users added through ActiveDirectory (AD), LDAP, Dynamic user addition, users created via e-mail Requests has been provided. Make sure that the notification under Admin >> Notification Rules >> Send Self-service login details is enabled before performing the import so that LA user details will be notified to users through email.” Timeline ======= 18-Apr-2017 – Notification to Vendor 19-Apr-2017 – Response from Vendor 31-Jan-2017 – Vulnerability fixed by Vendor 19-May-2017 – Still no clear publication on this backdoor |