Code Injection

Category: Command & Code Injection
Severity: Critical

Description

Injection of malicious code that gets executed within the MCP server environment, enabling attackers to execute arbitrary code and compromise the application runtime.

Technical Details

Attack Vector

  • Dynamic code execution vulnerabilities
  • Script injection attacks
  • Runtime code manipulation
  • Interpreter exploitation

Common Techniques

  • Dynamic code evaluation
  • Script injection
  • Template injection
  • Serialization attacks

Impact

  • Application Compromise: Control over application execution
  • Runtime Manipulation: Modification of application behavior
  • Data Access: Access to application data and memory
  • System Access: Potential system-level access through application

Detection Methods

Code Analysis

  • Monitor dynamic code execution
  • Track script evaluation
  • Detect code injection patterns
  • Analyze code execution flow

Runtime Monitoring

  • Monitor application behavior
  • Track execution patterns
  • Detect runtime anomalies
  • Analyze code execution context

Mitigation Strategies

Code Security

  • Avoid dynamic code execution
  • Use safe evaluation methods
  • Implement code validation
  • Deploy code sandboxing

Runtime Protection

  • Use runtime security controls
  • Implement execution monitoring
  • Deploy code integrity checks
  • Monitor application behavior

Real-World Examples

Example 1: Dynamic Code Evaluation

def execute_formula(formula):
    # Vulnerable dynamic code execution
    result = eval(formula)
    
    # Attack: formula = "__import__('os').system('rm -rf /')"
    # Executed: __import__('os').system('rm -rf /')

Example 2: Template Injection

def generate_report(template, data):
    # Vulnerable template processing
    template_str = f"Result: {template}"
    result = eval(template_str)
    
    # Attack: template = ""
    # Executed: Template injection leading to code execution

Example 3: Serialization Attack

def process_data(serialized_data):
    # Vulnerable deserialization
    data = pickle.loads(serialized_data)
    
    # Attack: serialized_data contains malicious pickled object
    # Executed: Code execution during deserialization

References & Sources

  • Philippe Bogaerts - “The Security Risks of Model Context Protocol (MCP)”
  • Strobes Security - “MCP and Its Critical Vulnerabilities”
  • Structured MCP Threats - Comprehensive threat landscape analysis

Code injection attacks target the application runtime itself, enabling sophisticated attacks that can compromise the entire MCP server environment.