CVE-2025-47277

Comprehensive Technical Analysis of CVE-2025-47277

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2025-47277

CVSS Score: 9.8

Severity: Critical

Description: The vulnerability affects vLLM, an inference and serving engine for large language models (LLMs), specifically in versions 0.6.5 through 0.8.4. The issue arises when using the PyNcclPipe KV cache transfer integration with the V0 engine. The TCPStore interface in PyTorch listens on all interfaces by default, exposing the system to potential unauthorized access. This vulnerability allows the TCPStore to bind to all network interfaces, regardless of the specified IP address, which was intended to be limited to a private network.

Impact:

• Confidentiality: High
• Integrity: High
• Availability: High

The high CVSS score of 9.8 indicates a critical vulnerability that could lead to significant security risks, including unauthorized access, data breaches, and potential disruption of services.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

1. Network-Based Attacks: An attacker could exploit the vulnerability by scanning for open TCPStore interfaces and attempting to connect to them. This could lead to unauthorized access to the KV cache and potentially other sensitive data.
2. Man-in-the-Middle (MitM) Attacks: An attacker could intercept and manipulate the data being transmitted between distributed nodes, leading to data corruption or unauthorized data access.
3. Denial of Service (DoS): An attacker could flood the TCPStore interface with malicious traffic, causing the service to become unavailable.

Exploitation Methods:

• Network Scanning: Using tools like Nmap to identify open TCPStore interfaces.
• Packet Sniffing: Capturing and analyzing network traffic to extract sensitive data.
• Malicious Payloads: Sending crafted packets to exploit the vulnerability and gain unauthorized access.

3. Affected Systems and Software Versions

Affected Software:

• vLLM versions 0.6.5 through 0.8.4

Affected Configurations:

• Environments using the PyNcclPipe KV cache transfer integration with the V0 engine.

Unaffected Configurations:

• Other configurations of vLLM that do not use the PyNcclPipe integration.

4. Recommended Mitigation Strategies

Immediate Mitigation:

1. Upgrade to Version 0.8.5: Upgrade vLLM to version 0.8.5 or later, which includes the fix to limit the TCPStore socket to the specified private interface.
2. Network Segmentation: Ensure that the TCPStore interface is only accessible from trusted, private networks.
3. Firewall Rules: Implement firewall rules to restrict access to the TCPStore interface to only authorized IP addresses.

Long-Term Mitigation:

1. Regular Security Audits: Conduct regular security audits and vulnerability assessments to identify and mitigate similar issues.
2. Patch Management: Implement a robust patch management process to ensure timely updates and patches are applied.
3. Intrusion Detection Systems (IDS): Deploy IDS to monitor network traffic for suspicious activities and potential exploitation attempts.

5. Impact on Cybersecurity Landscape

Immediate Impact:

• Organizations using vLLM in the affected configurations are at high risk of unauthorized access and data breaches.
• The vulnerability highlights the importance of secure network configurations and the need for timely patching.

Long-Term Impact:

• Increased awareness of the risks associated with default configurations that listen on all interfaces.
• Emphasis on the need for secure coding practices and thorough testing of network-related functionalities.
• Potential for similar vulnerabilities to be discovered in other software that relies on PyTorch or similar frameworks.

6. Technical Details for Security Professionals

Vulnerability Details:

• The TCPStore interface in PyTorch listens on all interfaces by default, regardless of the specified IP address.
• The vulnerability arises from the misconfiguration in the PyNcclPipe KV cache transfer integration, which was intended to be limited to a private network.

Fix Implementation:

• In version 0.8.5, vLLM was updated to force the TCPStore instance to bind its socket to the specified private interface, ensuring that it is not exposed to unauthorized access.

Code References:

• GitHub Commit
• GitHub Pull Request
• Security Advisory

Documentation:

• vLLM Security Documentation

Conclusion: CVE-2025-47277 is a critical vulnerability that underscores the importance of secure network configurations and timely patching. Organizations using vLLM should prioritize upgrading to version 0.8.5 and implementing robust security measures to mitigate the risk of unauthorized access and data breaches.