CVE-2025-6514: mcp-remote OS Command Injection RCE Flaw

CVE-2025-6514 Overview

mcp-remote is exposed to OS command injection when connecting to untrusted MCP servers due to crafted input from the authorization_endpoint response URL. This vulnerability can be exploited over a network, requires user interaction, and results in high confidentiality, integrity, and availability impacts.

Critical Impact
This vulnerability could allow attackers to execute arbitrary commands on the server, potentially leading to complete system compromise.

Affected Products

mcp-remote (specific versions not detailed)

Discovery Timeline

2025-07-09 - CVE-2025-6514 published to NVD
2025-07-10 - Last updated in NVD database

Technical Details for CVE-2025-6514

Vulnerability Analysis

The vulnerability in mcp-remote stems from improper input validation within the authorization endpoint response handling. Specifically, crafted input can inject operating system commands which are executed with the privileges of the mcp-remote process.

Root Cause

The root cause is the inadequate sanitization of user inputs in the authorization endpoint response URL. This leads to command injection when connected to malicious MCP servers.

Attack Vector

This command injection vulnerability can be exploited over a network, given that the attacker can trick a user or a system into interacting with a malicious MCP server.

python

# Example exploitation code (sanitized)
import requests
url = "http://malicious-server.com"
response = requests.get(url + "/auth?cmd=uname -a")
print(response.text)

Detection Methods for CVE-2025-6514

Indicators of Compromise

Unusual outbound network traffic to unknown MCP servers
Unexpected system commands in logs
Changes to system files or configurations

Detection Strategies

Security tools can flag unexpected outbound traffic patterns, especially to known indicators of malicious MCP servers. File integrity monitoring (FIM) can detect unauthorized changes.

Monitoring Recommendations

Implement network intrusion detection systems (NIDS) to monitor traffic patterns and enable logging and analysis of command execution using audit frameworks.

How to Mitigate CVE-2025-6514

Immediate Actions Required

Restrict network access to known and trusted MCP servers
Enable application whitelisting to prevent unauthorized command execution
Conduct regular code reviews and security testing

Patch Information

Monitor vendor communications for security patches addressing this vulnerability and apply them immediately upon release.

Workarounds

Consider using network-level firewall rules to block unauthorized MCP server connections and sanitize input at application level where possible.

bash

# Configuration example
iptables -A OUTPUT -p tcp -d malicious-server.com -j DROP