Bug 1309686

Summary: jboss: java.rmi.server.UnicastRemoteObject deserialization opens RMI listening socket
Product: [Other] Security Response Reporter: Adam Mariš <amaris>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: dbhole, jshepherd, jvanek, security-response-team
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2021-10-21 00:50:03 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On:    
Bug Blocks: 1283513, 1309688    

Description Adam Mariš 2016-02-18 13:38:38 UTC 
It was found that by sending an appropriate serialized object, one can cause the target JVM to open a listening socket on a client-specified port, start a thread to process requests, and have limited execution of specific code - which could be used for a DoS.

java.rmi.server.UnicastRemoteObject is a Serializable object whose readObject() methods calls exportObject() which will open a TCP listening socket on the port specified by the 'port' field and listen for RMI requests. Depending on the 'java.rmi.server.hostname' property and environment it may be localhost-only or remotely accessible. If enough requests are sent, it could lead to starvation of local port numbers, file descriptors and threads. If that open socket is not protected from remote access (say by a firewall), an attacker can send RMI invocations to it.
Comment 3 Jason Shepherd 2016-02-23 04:21:37 UTC 
We were able to reproduce a starvation of local port numbers, file descriptors and threads, however we could not bind remote objects into the RMI Server created by an exploit of this flaw. Therefore we're treating this issue as a moderate impact, DoS flaw only.