# Security Analysis: Agent Schema and Validation System

## Overview
This document provides a comprehensive security analysis of the claude-mpm agent validation system, highlighting security features, considerations, and recommendations.

## Schema Security Features (agent_schema.json)

### 1. Input Validation
- **Strict Type Enforcement**: All fields have explicit types preventing type confusion attacks
- **Pattern Validation**: Agent IDs use pattern `^[a-z][a-z0-9_]*$` preventing injection attacks
- **Enum Restrictions**: Tools and models restricted to known safe values
- **Length Limits**: All string fields have min/max length to prevent memory exhaustion
  - Instructions: max 8000 characters
  - Name: max 50 characters
  - Description: max 200 characters

### 2. Resource Controls
- **Memory Limits**: 512MB-8192MB range prevents OOM attacks
- **CPU Limits**: 10%-100% prevents resource hogging
- **Timeout Limits**: 30s-3600s prevents infinite operations
- **Token Limits**: 1000-200000 prevents API abuse

### 3. Access Controls
- **Network Access**: Default false, explicit opt-in required
- **File Access Paths**: Explicit read/write path restrictions
- **Tool Access**: Enumerated list prevents arbitrary tool usage
- **Additional Properties**: Set to false preventing field injection

### 4. Dangerous Tool Combinations
The schema allows these potentially dangerous combinations:
- **Bash + Write**: Can create and execute arbitrary scripts
- **docker + kubectl**: Container escape potential
- **aws + gcloud + azure**: Multiple cloud access increases attack surface

## Validator Security Features (agent_validator.py)

### 1. File Operation Security
- **Path Validation**: Checks file exists and is regular file
- **File Size Limits**: 1MB max prevents memory exhaustion
- **Symlink Protection**: Skips symlinks to prevent directory traversal
- **Directory Limits**: Max 100 files per directory prevents DoS

### 2. Business Rule Security
- **Double Validation**: Schema + business rules for defense in depth
- **ID Format Checking**: Additional validation beyond schema pattern
- **Resource Tier Validation**: Ensures limits match tier constraints
- **Tool Compatibility**: Validates dangerous tool combinations

### 3. Migration Security
- **Privilege Escalation Prevention**: Flags dangerous tools added during migration
- **Functionality Preservation**: Ensures security constraints maintained
- **Instruction Validation**: Prevents loss of security instructions

## Security Recommendations

### 1. Immediate Improvements
```python
# Add to validator.py
def _validate_path_injection(self, path: str) -> bool:
    """Prevent path traversal attacks"""
    if '..' in path or path.startswith('/'):
        return False
    return True

def _validate_command_injection(self, value: str) -> bool:
    """Prevent command injection in string values"""
    dangerous_chars = ['$', '`', ';', '&', '|', '>', '<']
    return not any(char in value for char in dangerous_chars)
```

### 2. Schema Enhancements
```json
{
  "capabilities": {
    "properties": {
      "sandbox_mode": {
        "type": "boolean",
        "default": true,
        "description": "Run agent in sandboxed environment"
      },
      "max_file_size": {
        "type": "integer",
        "default": 10485760,
        "description": "Maximum file size agent can read/write (10MB default)"
      }
    }
  }
}
```

### 3. Audit Logging
```python
def validate_agent(self, agent_data: Dict[str, Any]) -> ValidationResult:
    # Add security audit logging
    audit_log = {
        "timestamp": datetime.utcnow().isoformat(),
        "agent_id": agent_data.get("id"),
        "tools": agent_data.get("capabilities", {}).get("tools", []),
        "network_access": agent_data.get("capabilities", {}).get("network_access", False),
        "validation_result": "pending"
    }
    # Log to security audit trail
```

### 4. Runtime Security Checks
- Implement runtime validation of actual tool usage vs declared tools
- Monitor resource usage against declared limits
- Validate file access against declared paths
- Check for privilege escalation attempts

## Potential Security Issues

### 1. Missing Validations
- No validation of hook configurations
- No validation of file path patterns for malicious patterns
- No rate limiting on validation operations
- No cryptographic signing of agent configurations

### 2. Information Disclosure
- Error messages may reveal system paths
- Schema version in metadata could aid attackers
- No sanitization of user-provided descriptions

### 3. Trust Boundaries
- No verification of agent template sources
- No integrity checking of loaded schemas
- Migration process trusts old configurations

## Security Best Practices for Agent Authors

1. **Principle of Least Privilege**: Only request tools actually needed
2. **Avoid Dangerous Combinations**: Don't combine Bash with Write unless essential
3. **Explicit Path Restrictions**: Always specify file access paths
4. **Network Isolation**: Only enable network_access when required
5. **Resource Limits**: Set appropriate limits for agent workload
6. **Input Sanitization**: Never trust user input in agent instructions
7. **Secure Defaults**: Start with minimal permissions and add as needed

## Compliance Considerations

### OWASP Top 10 Coverage
- **A01:2021 Broken Access Control**: ✓ Tool and file access restrictions
- **A02:2021 Cryptographic Failures**: ⚠️ No encryption of agent configs
- **A03:2021 Injection**: ✓ Pattern validation, enum restrictions
- **A04:2021 Insecure Design**: ✓ Defense in depth validation
- **A05:2021 Security Misconfiguration**: ✓ Secure defaults, explicit opt-in
- **A06:2021 Vulnerable Components**: ⚠️ No component version checking
- **A07:2021 Identification and Authentication**: N/A (handled elsewhere)
- **A08:2021 Software and Data Integrity**: ⚠️ No integrity verification
- **A09:2021 Security Logging**: ⚠️ Limited security event logging
- **A10:2021 SSRF**: ✓ Network access controls

## Conclusion

The claude-mpm validation system implements strong security controls through:
- Strict schema validation with type safety
- Resource limits preventing DoS attacks
- Access controls for tools and files
- Defense in depth with multiple validation layers

Key areas for improvement:
- Cryptographic signing of configurations
- Enhanced audit logging
- Runtime security monitoring
- Integrity verification