Red Hat JBoss EAP - Deserialization of Untrusted Data

Security Advisory           @ Mediaservice.net Srl

(#05, 23/11/2016)           Data Security Division

 

         Title:	Red Hat JBoss EAP deserialization of untrusted data 

   Application:	JBoss EAP 5.2.X and prior versions

   Description:	The application server deserializes untrusted data via the

                JMX Invoker Servlet. This can lead to a DoS via resource

                exhaustion and potentially remote code execution.

        Author: Federico Dotta <federico.dotta@mediaservice.net>

                Maurizio Agazzini <inode@mediaservice.net>

 Vendor Status: Will not fix

 CVE Candidate: The Common Vulnerabilities and Exposures project has assigned

                the name CVE-2016-7065 to this issue.     

    References: http://lab.mediaservice.net/advisory/2016-05-jboss.txt

                http://lab.mediaservice.net/code/jboss_payload.zip

                https://bugzilla.redhat.com/show_bug.cgi?id=1382534



1. Abstract.



JBoss EAP's JMX Invoker Servlet is exposed by default on port 8080/TCP. The

communication employs serialized Java objects, encapsulated in HTTP

requests and responses.



The server deserializes these objects without checking the object type. This 

behavior can be exploited to cause a denial of service and potentially 

execute arbitrary code.



The objects that can cause the DoS are based on known disclosed payloads

taken from:



- https://gist.github.com/coekie/a27cc406fc9f3dc7a70d



Currently there is no known chain that allows code execution on JBoss EAP,

however new chains are discovered every day.



2. Example Attack Session.



Submit an authenticated POST request to the JMX Invoker Servlet URL (for 

example: http://localhost:8080/invoker/JMXInvokerServlet) with one of the 

following objects in the body of the request:



    * 01_BigString_limited.ser: it's a string object; the server will

      reply in a normal way (object size similar to the next one).

    * 02_SerialDOS_limited.ser: the application server will require

      about 2 minutes to execute the request with 100% CPU usage.

    * 03_BigString.ser: it's a string object; the server will

      reply in a normal way (object size similar to the next one).

    * 04_SerialDOS.ser: the application server will require an 

      unknown amount of time to execute the request with 100% CPU usage.



3. Affected Platforms.



This vulnerability affects versions 4 and 5 of JBoss EAP.



4. Fix.



Red Hat will not fix the issue because JBoss EAP 4 is out of maintenance 

support and JBoss EAP 5 is close to the end of its maintenance period. 



5. Proof Of Concept.



See jboss_payload.zip (40842.zip) and Example Attack Session above.



http://lab.mediaservice.net/code/jboss_payload.zip

https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/sploits/40842.zip



6. Timeline



06/10/2016 - First communication sent to Red Hat Security Response Team

07/10/2016 - Red Hat Security Response Team response, Bug 1382534 

23/11/2016 - Security Advisory released



Copyright (c) 2016 @ Mediaservice.net Srl. All rights reserved.





Proof of Concept:

https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/sploits/40842.zip