A recent vulnerability (CVE-2023-46604) has been discovered in the Java OpenWire protocol marshaller, which could lead to Remote Code Execution (RCE). This security flaw enables a remote attacker with network access to either a Java-based OpenWire broker or client to execute arbitrary shell commands. The attacker can manipulate the serialized class types in the OpenWire protocol to cause either the client or the broker (respectively) to instantiate any class on the classpath. To address this issue, users are advised to upgrade their brokers and clients to version 5.15.16, 5.16.7, 5.17.6, or 5.18.3.

Exploit Details

The vulnerability exists due to the insecure deserialization of serialized class types in the OpenWire protocol, allowing an attacker to inject malicious content into the classpath and leverage this to execute arbitrary shell commands. Here's a simplified example of how this exploit works:

// Assuming a Java OpenWire client/broker is already set up
public void deserializeAndExecute(ObjectInputStream in) {
    try {
        Object deserialized = in.readObject();
        if (deserialized instanceof Executable) {
            ((Executable) deserialized).execute();
        }
    } catch (IOException | ClassNotFoundException e) {
        e.printStackTrace();
    }
}

In this example, the deserializeAndExecute function simply reads an object from the provided ObjectInputStream and, if the object implements the Executable interface, it calls the execute() method, potentially running arbitrary shell commands.

For more information on the specific proof-of-concept for this vulnerability, refer to the original report on the CVE details page.

Mitigation and Patch Details

To mitigate this vulnerability, users should upgrade their Java OpenWire brokers and clients to version 5.15.16, 5.16.7, 5.17.6, or 5.18.3, as these versions contain a security patch for this issue. The respective release notes provide information on the fixes, new features, and other improvements included in each release, which can be found here:

- 5.15.16 release notes
- 5.16.7 release notes
- 5.17.6 release notes
- 5.18.3 release notes

The patch works by implementing secure deserialization practices, such as restricting the classes that can be deserialized and adding proper input validation and whitelisting.

Conclusion

In conclusion, the CVE-2023-46604 vulnerability in the Java OpenWire protocol marshaller poses a significant security risk, as it allows remote attackers to execute arbitrary shell commands. However, upgrading to the latest broker and client versions (5.15.16, 5.16.7, 5.17.6, or 5.18.3) ensures protection against this exploit. Regularly updating software and keeping an eye on security news are essential practices to maintain a secure environment.

Timeline

Published on: 10/27/2023 15:15:14 UTC
Last modified on: 11/20/2023 22:15:07 UTC