Performing SCADA HMI Security Assessment

When to Use

• When assessing the security posture of HMI systems in SCADA/DCS environments
• When evaluating web-based HMI interfaces for common web vulnerabilities
• When auditing HMI authentication, authorization, and session management
• When testing communication security between HMIs and PLCs/RTUs
• When preparing for IEC 62443 or NERC CIP compliance assessments

Do not use for testing HMIs in active production without a maintenance window and rollback plan, for PLC-level protocol analysis (see performing-s7comm-protocol-security-analysis), or for general web application testing on non-OT systems.

Prerequisites

• HMI system inventory with vendor, version, and network configuration details
• Lab or test environment mirroring production HMI setup (preferred for active testing)
• Authorization from plant operations for testing during maintenance windows
• NIST SP 800-82 and IEC 62443 security requirements documentation
• Network capture capability on HMI-to-PLC communication segment

Workflow

Step 1: Assess HMI Attack Surface

#!/usr/bin/env python3
"""SCADA HMI Security Assessment Tool.

Evaluates HMI security across authentication, communication,
configuration, and web interface categories aligned with
IEC 62443 and NIST SP 800-82 requirements.
"""

import json
import sys
from datetime import datetime
from typing import Dict, List

try:
    import requests
except ImportError:
    print("Install requests: pip install requests")
    sys.exit(1)


class HMISecurityAssessment:
    """Performs security assessment of SCADA HMI systems."""

    def __init__(self, hmi_info: dict):
        self.hmi_info = hmi_info
        self.findings = []
        self.checks_run = 0
        self.checks_passed = 0

    def check_authentication(self):
        """Assess HMI authentication mechanisms."""
        checks = [
            {
                "id": "AUTH-01",
                "name": "Password complexity enforcement",
                "iec62443_ref": "ISA-62443-3-3 SR 1.7",
                "description": "HMI must enforce minimum password complexity requirements",
                "test": "Verify minimum length >= 8, complexity rules, history >= 5",
            },
            {
                "id": "AUTH-02",
                "name": "Account lockout policy",
                "iec62443_ref": "ISA-62443-3-3 SR 1.11",
                "description": "HMI must lock accounts after failed login attempts",
                "test": "Verify lockout after 5 failed attempts, lockout duration >= 15 min",
            },
            {
                "id": "AUTH-03",
                "name": "Default credentials changed",
                "iec62443_ref": "ISA-62443-3-3 SR 1.5",
                "description": "All default vendor credentials must be changed",
                "test": "Attempt login with known vendor defaults (admin/admin, operator/operator)",
            },
            {
                "id": "AUTH-04",
                "name": "Role-based access control",
                "iec62443_ref": "ISA-62443-3-3 SR 2.1",
                "description": "HMI must separate operator, engineer, and admin roles",
                "test": "Verify operator role cannot access engineering functions",
            },
            {
                "id": "AUTH-05",
                "name": "Session timeout enforcement",
                "iec62443_ref": "ISA-62443-3-3 SR 1.12",
                "description": "HMI sessions must time out after inactivity",
                "test": "Verify session timeout <= 15 minutes for operator, <= 5 for admin",
            },
            {
                "id": "AUTH-06",
                "name": "Multi-factor authentication for remote access",
                "iec62443_ref": "ISA-62443-3-3 SR 1.13",
                "description": "Remote HMI access requires MFA",
                "test": "Verify MFA is enforced for all non-local HMI connections",
            },
        ]

        print(f"\n--- AUTHENTICATION ASSESSMENT ---")
        for check in checks:
            self.checks_run += 1
            print(f"  [{check['id']}] {check['name']}")
            print(f"    Ref: {check['iec62443_ref']}")
            print(f"    Test: {check['test']}")

    def check_communication_security(self):
        """Assess HMI-to-PLC communication security."""
        checks = [
            {
                "id": "COMM-01",

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