CVE-2025-29783

Remediation/Mitigation Strategy for CVE-2025-29783 (vLLM Remote Code Execution)

This document outlines the remediation and mitigation strategy for CVE-2025-29783, a critical vulnerability in vLLM (versions prior to 0.8.0) when configured to use Mooncake for distributed KV storage.

1. Vulnerability Description:

  • Vulnerability: Remote Code Execution (RCE) via unsafe deserialization.
  • Affected Software: vLLM versions prior to 0.8.0 when configured with Mooncake.
  • Cause: Unsafe deserialization of data received over ZMQ/TCP. Mooncake, used to distribute key-value data across distributed hosts in a vLLM cluster, exposes this insecure deserialization endpoint directly on all network interfaces by default.
  • Attack Vector: An attacker can send specially crafted, malicious serialized objects to the vulnerable ZMQ/TCP endpoint. When deserialized, this code will be executed by the vLLM process, granting the attacker control over the affected host.

2. Severity:

  • Severity Score (CVSS v3.x): 10.0 (Critical)
  • CVSS Vector: (Based on description, inferred. The provided data doesn’t fully populate the CVSS vector. The following is a plausible and conservative estimate.) CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
  • Explanation: This vulnerability allows for unauthenticated remote code execution. An attacker on the network can compromise the vLLM host without requiring any user interaction or credentials. The impact is complete loss of confidentiality, integrity, and availability. The Scope is Changed because the attack targets the vLLM process but can affect the entire system it runs on.

3. Known Exploits:

  • The provided information indicates that this vulnerability is exploitable and has been assigned a CVE. While specific exploit code is not detailed in the provided information, the nature of an “unsafe deserialization” vulnerability makes it highly likely that exploit code exists or can be easily created.
  • The fact that this endpoint is exposed over ZMQ/TCP on all network interfaces significantly increases the attack surface and likelihood of exploitation.

4. Remediation Strategy:

  • Primary Solution: Upgrade to vLLM 0.8.0 or later: The vendor has explicitly stated that this vulnerability is fixed in version 0.8.0. This is the required action. Immediately upgrade all vLLM deployments utilizing Mooncake to version 0.8.0 or a later patched version. # Example Upgrade command (may vary depending on your installation method) pip install vllm –upgrade

5. Mitigation Strategy (Interim Measures - Use until Upgrade is Complete):

If an immediate upgrade is not possible, the following mitigation steps MUST be implemented as quickly as possible:

  • Network Segmentation & Firewalling: Restrict network access to the ZMQ/TCP endpoint used by Mooncake (investigate which port Mooncake is using and block access to it). Place the vLLM nodes utilizing Mooncake in a highly isolated network segment with strict firewall rules. Only allow necessary traffic from trusted sources. This is crucial.
  • Disable Mooncake (if possible): If your vLLM deployment can function without distributed KV storage, temporarily disable Mooncake entirely. This will completely eliminate the vulnerability. This might require reconfiguring vLLM to run in a single-node configuration.
  • Monitor for Suspicious Activity: Implement robust monitoring on the vLLM hosts. Specifically, monitor for:
    • Unexpected network connections, especially to/from the ZMQ/TCP port used by Mooncake.
    • Unexpected process creation or execution.
    • High CPU or memory usage spikes.
    • Unusual file system modifications.
  • Intrusion Detection/Prevention Systems (IDS/IPS): Configure your IDS/IPS to detect and block malicious traffic targeting the vLLM hosts. Look for patterns indicative of deserialization attacks.
  • Implement least privilege principle: Ensure that the vLLM process is running with the least privileges necessary. Limit the permissions of the user account under which vLLM is executed. This will limit the impact of a successful RCE attack.

6. Monitoring and Verification:

  • After applying the remediation or mitigation steps, thoroughly test the vLLM deployment to ensure that it is functioning correctly.
  • Continuously monitor the vLLM systems for any signs of compromise or suspicious activity.
  • Regularly scan the vLLM hosts for vulnerabilities and apply security patches as they become available.
  • Retest the configuration once the upgrade has been completed to ensure the vulnerability has been eliminated.

7. Communication:

  • Communicate this vulnerability and the remediation/mitigation steps to all relevant stakeholders, including system administrators, security teams, and developers.
  • Provide clear instructions and timelines for implementing the necessary changes.

8. Rollback Plan:

  • Ensure that you have a rollback plan in place in case the upgrade or mitigation steps cause any unforeseen issues.
  • This plan should include steps for reverting to the previous version of vLLM and restoring the original network configuration.

Important Considerations:

  • Urgency: This is a critical vulnerability, and remediation/mitigation efforts should be prioritized accordingly.
  • Accuracy: Ensure the port that Mooncake is running on is accurately identified to correctly configure firewalls. Consult the Mooncake documentation if needed.
  • Completeness: Fully test all aspects of the vLLM deployment after applying remediation/mitigation steps.
  • Ongoing Security: This is not a one-time fix. Continue to monitor the security of your vLLM deployments and apply security patches promptly.
  • Consult Vendor Documentation: Always refer to the official vLLM and Mooncake documentation for the most up-to-date information and best practices.

Assigner

Date

  • Published Date: 2025-03-19 16:15:32
  • Updated Date: 2025-03-19 16:15:32

More Details

CVE-2025-29783