MCP Guard

Professional Security Scanner for Model Context Protocol Servers

The first open-source security scanner specifically designed for MCP servers

Quick Start • Features • Documentation • Examples • Contributing

Overview

MCP Guard is a comprehensive security assessment tool that identifies vulnerabilities in Model Context Protocol (MCP) servers through static analysis, dynamic testing, and intelligent fuzzing. Built for security professionals and developers working with AI systems.

Why MCP Guard?

• First-of-its-kind: Purpose-built for MCP server security assessment
• Universal Support: Works with Python, Node.js, Go, and Docker-based MCP servers
• Professional Scoring: Implements both CVSS v4.0 and AIVSS (AI Vulnerability Scoring System)
• Production Ready: Enterprise-grade features with comprehensive reporting

Quick Start

# Clone and setup
git clone https://github.com/SaravanaGuhan/mcp-guard.git
cd mcp-guard
pip install -r requirements.txt

# Scan an MCP server
python mcp_scanner.py https://github.com/openbnb-org/mcp-server-airbnb

That's it! MCP Guard will automatically detect the server type, perform comprehensive security analysis, and provide detailed vulnerability reports.

Features

🔍 Comprehensive Analysis

• Static Analysis: Pattern-based vulnerability detection
• Dynamic Testing: Live server security assessment
• Dependency Scanning: Known CVE identification
• Protocol Validation: MCP-specific security checks

🎯 Universal Server Support

• Python: Django, Flask, FastAPI MCP servers
• Node.js/TypeScript: Express, Koa MCP implementations
• Go: Native Go MCP servers
• Docker: Containerized MCP deployments

📊 Professional Scoring

• CVSS v4.0: Industry-standard vulnerability scoring
• AIVSS: AI-specific vulnerability assessment
• Risk Analysis: Business impact evaluation
• Remediation Prioritization: Intelligent vulnerability ranking

🚀 Enterprise Ready

• CI/CD Integration: GitHub Actions, Jenkins support
• Multiple Formats: JSON, SARIF, JUnit XML reports
• Security Gates: Automated pass/fail criteria
• Batch Processing: Multi-repository analysis

Vulnerability Detection

MCP Guard identifies security issues across multiple categories:

Sample Output

================================================================================
MCP GUARD SECURITY ASSESSMENT REPORT
================================================================================
Target: https://github.com/openbnb-org/mcp-server-airbnb
Server Type: Node.js MCP Server
Scan Duration: 45.2 seconds

VULNERABILITY SUMMARY
├── Total Issues: 5
├── Critical: 1    High: 2    Medium: 1    Low: 1
├── CVSS v4.0 Average: 6.8
└── Overall Risk: HIGH

CRITICAL SEVERITY FINDINGS
┌─────────────────────────────────────────────────────────────────────────────
│ [CVE-2024-XXXX] Command Injection in Tool Handler
│ CVSS Score: 9.1 (CRITICAL)  |  AIVSS Score: 8.7 (AI_HIGH)
│ File: src/tools/system.js:45
│ 
│ Description: Unsanitized user input passed to child_process.exec()
│ Impact: Remote code execution on server
│ Remediation: Implement input validation and use parameterized commands
└─────────────────────────────────────────────────────────────────────────────

RECOMMENDATIONS
• Implement comprehensive input validation for all MCP tool parameters
• Update 3 vulnerable dependencies (express, lodash, axios)
• Enable security headers and HTTPS enforcement
• Add rate limiting to prevent abuse

Scan completed successfully ✓

Installation

Prerequisites

• Python 3.8 or higher
• Internet connection for repository downloads
• Git (optional, for development)

Standard Installation

git clone https://github.com/SaravanaGuhan/mcp-guard.git
cd mcp-guard
pip install -r requirements.txt

Development Installation

git clone https://github.com/SaravanaGuhan/mcp-guard.git
cd mcp-guard
pip install -e .
pip install -r requirements-dev.txt

Docker Installation

docker build -t mcp-guard .
docker run -v $(pwd):/workspace mcp-guard https://github.com/target/mcp-server

Usage Examples

Basic Scanning

# Scan a GitHub repository
python mcp_scanner.py https://github.com/cloudflare/mcp-server-cloudflare

# Static analysis only
python mcp_scanner.py --scan-type static https://github.com/target/repo

# Dynamic analysis only  
python mcp_scanner.py --scan-type dynamic https://github.com/target/repo

# Output to JSON
python mcp_scanner.py --output report.json https://github.com/target/repo

Advanced Usage

from mcp_scanner import UniversalMCPScanner

scanner = UniversalMCPScanner()
results = scanner.scan_mcp_server(
    repo_url="https://github.com/target/mcp-server",
    scan_type="both"
)

print(f"Found {len(results['vulnerabilities'])} vulnerabilities")
print(f"Overall risk: {results['summary']['risk_assessment']['overall_risk']}")

Supported MCP Servers

MCP Guard has been tested with popular MCP server implementations:

Architecture

graph TB
    A[Repository URL] --> B[Repository Handler]
    B --> C[Server Type Detection]
    C --> D[Static Analysis Engine]
    C --> E[Dynamic Analysis Engine]
    D --> F[Vulnerability Scoring]
    E --> F
    F --> G[CVSS v4.0 Scoring]
    F --> H[AIVSS Scoring]
    G --> I[Report Generation]
    H --> I
    I --> J[JSON/Console Output]

Core Components

• Repository Handler: Downloads and analyzes repository structure
• Static Analysis Engine: Pattern-based vulnerability detection
• Dynamic Analysis Engine: Live server testing and fuzzing
• Vulnerability Scoring: CVSS v4.0 and AIVSS implementation
• Report Generator: Professional vulnerability reporting

Documentation

Contributing

We welcome contributions from the security and AI communities!

Ways to Contribute

• Report Bugs: Found an issue? Open a bug report
• Feature Requests: Have an idea? Request a feature
• Code Contributions: Submit pull requests for improvements
• Documentation: Help improve our documentation
• Testing: Test with new MCP servers and report results

Development Setup

git clone https://github.com/SaravanaGuhan/mcp-guard.git
cd mcp-guard
pip install -e ".[dev]"
pytest tests/

Security

MCP Guard is designed with security in mind:

• Safe Repository Handling: Secure download and cleanup processes
• Sandboxed Execution: Isolated dynamic analysis environment
• Input Validation: Protection against malicious repository content
• Resource Limits: CPU, memory, and time constraints
• Network Security: HTTPS-only downloads with timeout protection

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• MCP Community: For developing the Model Context Protocol
• Security Researchers: For vulnerability research and best practices
• Open Source Contributors: For making this project possible
• CVSS Working Group: For the CVSS v4.0 specification

Built with ❤️ for the MCP and Security Communities

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