OT-Specific Security Testing Frameworks for the Maritime Sector

The maritime sector relies heavily on Operational Technology (OT) systems to manage critical functions, such as navigation, engine control, cargo handling, and communication. While these systems improve efficiency and safety, their increased connectivity to IT networks and external systems also makes them attractive targets for cyberattacks. Ensuring the security of these OT systems is crucial to comply with regulations like IMO Resolution MSC.428(98), the NIS2 Directive, and industry best practices.

This article explores the importance of OT security testing in the maritime sector, introduces key OT-specific testing frameworks, and provides best practices for implementing effective security measures in OT environments.

1. What is Operational Technology (OT)?

Operational Technology (OT) refers to hardware and software systems that monitor and control physical processes, such as machinery and equipment. OT is commonly used in industrial settings, including shipping and maritime operations.

Examples of OT in the maritime sector include:

• Electronic Chart Display and Information System (ECDIS) – Digital navigation systems.

• Engine and Propulsion Control Systems – Systems managing engine operations and fuel efficiency.

• Cargo Management Systems – Equipment used to load, unload, and secure cargo.

• Automatic Identification Systems (AIS) – Systems that transmit ship position and identity information.

• Supervisory Control and Data Acquisition (SCADA) – Systems that control operations across multiple ship components.

Unlike traditional IT systems, OT systems often have strict uptime and safety requirements. As a result, security testing in OT environments requires specialised approaches to minimise disruptions while ensuring that vulnerabilities are identified and mitigated.

2. Why is OT Security Testing Important?

Cyberattacks targeting OT systems can have severe consequences, including:

• Loss of Control: Cyber attackers may disrupt or disable critical shipboard systems, affecting navigation, engine control, or cargo handling.

• Operational Downtime: Malicious software, such as ransomware, can halt operations, leading to significant financial losses and service delays.

• Safety Risks: Compromised OT systems can endanger crew safety, passengers, and cargo, as well as other vessels in the vicinity.

• Regulatory Non-Compliance: Failure to secure OT systems may result in non-compliance with regulations such as IMO MSC.428(98), NIS2, and SOLAS, leading to penalties, detentions, and reputational damage.

Regular security testing of OT systems is essential to mitigate these risks and maintain operational resilience.

3. Challenges of OT Security Testing in the Maritime Sector

Security testing in OT environments differs from traditional IT testing due to the unique characteristics of OT systems:

• High Availability Requirements: OT systems often operate 24/7 and are critical to ship operations. Testing must be conducted without causing downtime or disruptions.

• Legacy Systems: Many OT systems use outdated software and hardware that may not be compatible with modern security tools or updates.

• Limited Security Features: OT devices were often designed with functionality and safety in mind, rather than security. This makes them vulnerable to attacks that exploit weak access controls, unpatched vulnerabilities, and insecure communication protocols.

• Complex Environments: OT systems are often integrated with IT networks, creating complex interdependencies that can introduce additional risks.

To address these challenges, organisations should adopt specialised OT security testing frameworks that balance safety, uptime, and security.

4. OT-Specific Security Testing Frameworks

Several established frameworks provide guidance on securing and testing OT systems. These frameworks are designed to address the unique needs of industrial control systems (ICS) and critical infrastructure, including maritime OT environments.

4.1. NIST Cybersecurity Framework (NIST CSF)

The NIST Cybersecurity Framework is widely used across industries to manage and mitigate cybersecurity risks. It provides a flexible, risk-based approach with five core functions:

1. Identify: Understand the assets, systems, and processes that need protection.

2. Protect: Implement security measures to safeguard systems.

3. Detect: Monitor for anomalies and security events.

4. Respond: Develop procedures to contain and mitigate security incidents.

5. Recover: Restore operations and services following a cyber incident.

While NIST CSF applies to both IT and OT, it can be tailored to address OT-specific requirements, such as physical process monitoring and safety protocols.

4.2. IEC 62443 (ISA/IEC 62443)

The IEC 62443 series of standards, developed by the International Electrotechnical Commission (IEC), provides a comprehensive framework for securing industrial automation and control systems (IACS). It is particularly relevant for OT environments and includes guidance on:

• Security Levels: Defining security objectives based on risk assessments and system criticality.

• Component Security: Ensuring that individual OT devices meet security standards.

• System Integration: Managing security across interconnected OT and IT networks.

• Continuous Improvement: Regularly assessing and updating security measures.

IEC 62443 emphasises secure system design, access control, and incident response, making it highly applicable to maritime OT systems.

4.3. MITRE ATT&CK for ICS

The MITRE ATT&CK for ICS framework is a knowledge base of tactics, techniques, and procedures (TTPs) used by attackers to target industrial control systems. It categorises attacks into stages, such as:

• Initial access (e.g., exploiting remote access services).

• Execution (e.g., deploying malware on OT devices).

• Persistence (e.g., maintaining access to compromised systems).

• Impact (e.g., disrupting physical processes).

Security teams can use the framework to simulate realistic attack scenarios, identify vulnerabilities, and improve detection and response capabilities.

4.4. TIBER-EU (Threat Intelligence-Based Ethical Red Teaming)

Developed by the European Central Bank (ECB), the TIBER-EU framework is designed for critical infrastructure providers, including maritime organisations. It focuses on red team exercises that simulate advanced attacks to test an organisation's cyber resilience.

Key features of TIBER-EU include:

• Threat Intelligence: Customising attack simulations based on real-world threat data.

• Scenario-Based Testing: Conducting targeted tests on critical assets and processes.

• Collaboration: Engaging stakeholders across IT, OT, and risk management functions.

TIBER-EU helps organisations assess their ability to detect, respond to, and recover from sophisticated cyberattacks.

5. Best Practices for OT Security Testing

To ensure effective security testing of OT systems, maritime organisations should follow these best practices:

5.1. Conduct Risk Assessments

Identify critical OT assets, threats, and vulnerabilities through risk assessments. Focus on systems that could have the greatest impact on safety and operations if compromised.

5.2. Use Non-Disruptive Testing Methods

Perform security tests that minimise the risk of downtime or system failures. Techniques such as passive vulnerability scanning and protocol analysis can identify weaknesses without disrupting operations.

5.3. Collaborate Across Teams

Engage both IT and OT stakeholders in the testing process. Ensure that system operators, engineers, and cybersecurity teams work together to understand risks and implement appropriate security measures.

5.4. Implement Network Segmentation

Separate OT networks from IT networks to reduce the risk of lateral movement by attackers. Use firewalls, virtual LANs (VLANs), and access controls to limit communication between networks.

5.5. Regularly Update and Patch Systems

Develop patch management procedures for OT devices. Where patching is not feasible, implement compensating controls, such as intrusion detection systems and access restrictions.

6. Conclusion

Securing OT systems is critical to maintaining safety, operational continuity, and compliance in the maritime sector. By adopting OT-specific security testing frameworks, such as NIST CSF, IEC 62443, and MITRE ATT&CK for ICS, organisations can identify and mitigate vulnerabilities in their critical infrastructure. Regular testing, combined with a risk-based approach, helps ensure that OT systems remain resilient against evolving cyber threats.

For expert guidance on OT security testing, risk assessments, or compliance with maritime cybersecurity regulations, contact our cybersecurity specialists today.