CVE-2014-6043 : Détail

Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.

Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.

Mogwai Security Advisory MSA-2014-01 ---------------------------------------------------------------------- Title: ManageEngine EventLog Analyzer Multiple Vulnerabilities Product: ManageEngine EventLog Analyzer Affected versions: EventLog Analyzer 9.9 (Build 9002) on Windows/Linux Impact: critical Remote: yes Product link: http://www.manageengine.com/products/eventlog/ Reported: 18/04/2013 by: Hans-Martin Muench (Mogwai, IT-Sicherheitsberatung Muench) Vendor's Description of the Software: ---------------------------------------------------------------------- EventLog Analyzer provides the most cost-effective Security Information and Event Management (SIEM) software on the market. Using this Log Analyzer software, organizations can automate the entire process of managing terabytes of machine generated logs by collecting, analyzing, searching, reporting, and archiving from one central location. This event log analyzer software helps to mitigate internal threats, conduct log forensics analysis, monitor privileged users and comply to different compliance regulatory bodies by intelligently analyzing your logs and instantly generating a variety of reports like user activity reports, regulatory compliance reports, historical trend reports, and more. Business recommendation: ---------------------------------------------------------------------- During a penetration test, multiple vulnerabilities have been identified that are based on severe design/implementation flaws in the application. It is highly recommended not to use this software until a thorough security review has been performed by security professionals and all identified issues have been resolved. Vulnerability description: ---------------------------------------------------------------------- 1) Unauthenticated remote code execution ME EventLog Analyzer contains a "agentUpload" servlet which is used by Agents to send log data as zip files to the central server. Files can be uploaded without authentication and are stored/decompressed in the "data" subdirectory. As the decompress procedure is handling the file names in the ZIP file in a insecure way it is possible to store files in the web root of server. This can be used to upload/execute code with the rights of the application server. 2) Authorization issues The EventLog Analyzer web interface does not check if an authenticated has sufficient permissions to access certain parts of the application. A low privileged user (for example guest) can therefore access critical sections of the web interface, by directly calling the corresponding URLs. This can be used to access the database browser of the application which gives the attacker full access to the database. Proof of concept: ---------------------------------------------------------------------- 1) Unauthenticated remote code execution - Create a malicious zip archive with the help of evilarc[1] evilarc.py -d 2 -o unix -p webapps/event cmdshell.jsp - Send the malicious archive to the agentUpload servlet curl -F "[email protected]" http://172.16.37.131:8400/agentUpload - Enjoy your shell http://172.16.37.131:8400/cmdshell.jsp A working Metasploit module will be released next week. 2) Authorization issues - Log in as a low privileged user (for example guest/guest) - Directly call the URL of the database browser http://xxx.xxx.xxx.xxx:8400/event/runQuery.do Vulnerable / tested versions: ---------------------------------------------------------------------- EventLog Analyzer 8.2 (Build 8020) (Windows) EventLog Analyzer 8.2 (Build 8020) (Linux) EventLog Analyzer 9.0 (Build 9002) (Windows) EventLog Analyzer 9.0 (Build 9002) (Linux) Other versions might also be vulnerable. Disclosure timeline: ---------------------------------------------------------------------- 14/04/2013: Vulnerability discovery 18/04/2013: Informed vendor via ManageEngine Security Response Center (MESRC) Form 23/04/2013: Second try to contact MESRC, as we didn't receive any response from the first try. 23/04/2013: Response from vendor, they wait on some feedback from the development team 10/05/2013: Response from vendor, saying that this is rather a issue than a vulnerability, will fix it anyway 13/05/2013: Technical details including a working proof of concept send ManageEngine. 13/05/2013: Vendor response, say that they forward it to the development team 24/05/2013: Vendor response, saying that they will fix it in 2013 as they are "tightly scheduled on other priorities" 24/05/2013: Response from us, asking if we will be informed when the vulnerability is fixed 28/05/2013: Response from ManageEngine, saying that we must subscribe to their newsletter for release information 05/09/2013: Verification that exploit is still working with the current version 30/08/2014: Verification that exploit is still working with the current version 31/08/2014: Public release Solution: ---------------------------------------------------------------------- No known solution Workaround: ---------------------------------------------------------------------- 1) Unauthenticated remote code execution If agents are not used to collect log information, access to the servlet can be disabled by commenting out the following lines in the web.xml file (webapps/event/WEB-INF/web.xml) and restart the service. agentUpload com.adventnet.sa.agent.UploadHandlerServlet agentUpload /agentUpload 2) Authorization issues No workaround, reduce the attack surface by disabling unused low privileged accounts like "guest". Advisory URL: ---------------------------------------------------------------------- https://www.mogwaisecurity.de/en/lab/advisories/ References ---------------------------------------------------------------------- [1] evilarc https://github.com/ptoomey3/evilarc ---------------------------------------------------------------------- Mogwai, IT-Sicherheitsberatung Muench Steinhoevelstrasse 2/2 89075 Ulm (Germany) [email protected]