CVE-2023-36480 - Remote Code Execution in Aerospike Java Client – Exploit Analysis & Mitigation

On June 22, 2023, a critical vulnerability was announced affecting the Aerospike Java Client—a widely used library that allows Java applications to connect to Aerospike database servers. This vulnerability, tracked as CVE-2023-36480, exposes client systems to remote code execution (RCE) when connecting to a *malicious or compromised Aerospike server*. In this article, we’ll break down what the risk is, how it works, show example vulnerable code, and share ways you can protect your systems.

4.5.

Older versions of the client trust certain server-sent data, and will blindly deserialize Java objects from messages received over the network. If an attacker controls the server—say by spoofing DNS, controlling a proxy, or exploiting other infrastructure—they can send crafted objects. These objects are deserialized by the client app, and can trigger arbitrary code. In plain English: if your app talks to the wrong server, you could lose control of the machine!

Key Points

- Vulnerability exists only if Java client connects to a server controlled or manipulated by an attacker.

Background on Java Deserialization Attacks

Java applications often transport objects between servers or clients by serializing (turning into bytes) and deserializing (turning bytes back into objects). If untrusted data is deserialized, attackers can inject malicious objects that run code upon deserialization. This is a classic security anti-pattern.

In The Aerospike Java Client

Aerospike uses its own wire protocol, but some messages in those affected versions could include serialized Java objects. There’s no proper validation, so any object may be deserialized.

Exploit Scenario

1. Attacker lures or tricks a client to connect to a server they control. This could be through a DNS attack, MITM, or because the attacker is already on the network.

Malicious server sends a crafted response, embedding a Java serialized object.

3. The unsecured client code deserializes the payload—which, using exploit gadget chains available in the classpath, executes code on the client machine.

Vulnerable Code Example

This is a simplified illustration. The actual Aerospike code uses network socket streams.

import java.io.InputStream;
import java.io.ObjectInputStream;
import java.net.Socket;

public class VulnerableClient {

    public static void main(String[] args) throws Exception {
        Socket socket = new Socket("remote-malicious-server.com", 300);

        // WARNING: Never deserialize untrusted data!
        InputStream input = socket.getInputStream();
        ObjectInputStream objectInput = new ObjectInputStream(input);

        // The following line is the vulnerability
        Object obj = objectInput.readObject();

        System.out.println("Received object: " + obj);

        socket.close();
    }
}

In the real Aerospike client, similar logic exists for certain admin or system messages.

Proof-of-Concept (PoC) Exploit

For ethical reasons, we only sketch the core idea (do not use this for illegal purposes!).

1. Download a known Java deserialization gadget chain, such as ysoserial.

Example payload (using ysoserial)

java -jar ysoserial.jar CommonsCollections6 'calc' > payload.ser

Then, the fake server sends payload.ser to any connecting client expecting an admin or info object.

When the client deserializes this payload, the attacker's code runs.

4.5.

If you’re running any earlier version, update now.

Modify your build.gradle or pom.xml to require a safe version

<dependency>
    <groupId>com.aerospike</groupId>
    <artifactId>aerospike-client</artifactId>
    <version>7..</version>
</dependency>

Or, for Gradle

implementation 'com.aerospike:aerospike-client:7..'

Additional Mitigation

- Restrict Client Network Access: Only allow the client to communicate with trusted Aerospike servers.

References

- NVD Entry for CVE-2023-36480
- Aerospike Java Client Releases
- Detailed advisory
- ysoserial - Java Deserialization Exploits

Conclusion

CVE-2023-36480 is a serious threat to anyone running old versions of the Aerospike Java Client. If an attacker tricks your client into connecting to a fake server, they gain a direct avenue to run code on your host! Upgrade now and review your network security practices to stay safe.

*Have questions or need help with securing your Aerospike setup? Please contact your security team, or ask for more details below!*

Timeline

Published on: 08/04/2023 15:15:00 UTC
Last modified on: 08/09/2023 17:36:00 UTC