Industrial control systems (ICS) are vital in managing critical infrastructure. These systems’ increased connectivity and digitization have exposed them to new cyber threats, forcing organizations to prioritize their security. This blog post will explore the unique challenges in securing OT/ICS and explore strategies to safeguard them. 

The Importance of Securing OT/ICS Components

Many OT/ICS components are essential to the normal functioning of critical infrastructure and, hence, the economy. Let’s examine some of the most common OT/ICS components and why they must be protected.

Supervisory Control and Data Acquisition (SCADA) systems are computer-based control systems that monitor and manage industrial processes and critical infrastructure. These systems are widely deployed in sectors such as energy, water and wastewater management, oil and gas, transportation, manufacturing, and more. SCADA systems enable operators to supervise and control various devices and processes remotely, providing real-time data and facilitating automation for efficient operations.

If cybercriminals manage to compromise a SCADA system, it could lead to operational disruptions, production halts, and, in the worst-case scenario, potential harm to human life and the environment. The most well-known example of a SCADA compromise is the Stuxnet hack, in which the USA and Israel targeted the Iranian nuclear programs’ SCADA system, causing substantial damage.

Programmable Logic Controllers (PLCs) are specialized digital computers used in industrial automation to control and manage various processes and machinery. PLCs are programmable and highly configurable, making them essential components in various industries, including manufacturing, energy, transportation, and more. They receive input signals from sensors, process the data, and then output control signals to actuators, enabling them to automate and regulate complex industrial processes. A breach in PLC security could enable unauthorized control over machinery, leading to equipment damage or even industrial accidents.

Human-Machine Interfaces (HMIs) are user interfaces that facilitate interaction between humans and machines, allowing operators or users to monitor, control, and manage complex systems and processes. HMIs are integral to various industrial control systems, including the SCADA systems and programmable logic controllers (PLCs) we covered above. They provide a graphical representation of data and processes, enabling operators to receive real-time information, issue commands, and respond to alerts in industrial environments. If these interfaces are compromised, operators may receive manipulated data, leading to incorrect decisions and potential safety hazards.

Unique Challenges in Securing OT/ICS

Securing OT/ICS systems comes with unique challenges. They include but are not limited to:

  • Legacy Systems: Many critical infrastructures still rely on legacy OT/ICS technologies not designed with modern security considerations. These systems often lack built-in security features and are vulnerable to cyber threats.
  • Operational Continuity: Critical infrastructure facilities demand uninterrupted operations, making performing necessary updates and patch management challenging without disrupting essential services.
  • Converging IT and OT: The convergence of IT (Information Technology) and OT (Operational Technology) networks has expanded the attack surface, as previously isolated OT systems are now exposed to internet-based threats.
  • Limited Security Awareness: Operators and industrial personnel may not have sufficient cybersecurity knowledge, making them susceptible to social engineering attacks and unintentional security breaches.

Strategies for Safeguarding OT/ICS

Regular patch management is one of the most important ways to safeguard OT/ICS systems. A well-defined patch management process is critical to addressing known vulnerabilities while minimizing downtime and disruptions. However, it’s important to note that patching OT/ICS vulnerabilities is not as simple as patching more typical network infrastructures.

The first and most important step to patching OT/ICS systems is carrying out a comprehensive inventory of assets and risk assessment of threats, vulnerabilities, and potential impacts. Organizations should use a software bill of materials (SBOM). An SBOM is detailed guide to all the components of a software product and its relation to supply chains. Using an SBOM will help security teams understand their environment so they can better secure it.

The convergence of IT and OT systems has brought about unique challenges; organizations must segment systems wherever possible to ensure minimal disruption in the wake of an attack. Organizations must not treat attacks on IT/OCS in the same way as attacks on more traditional systems; the priority is maintaining safety, reliability, and performance (SRP), not data confidentiality (although this is still important for complying with regulations like GDPR).

Traditional vulnerability scanning tools can disrupt operations in a way that they wouldn’t regular IT systems. To ensure this doesn’t happen, organizations must use an OT-specific vulnerability assessment platform. They should also use automated, OT-specific vulnerability scanners in conjunction with manual CVE reviews to achieve the necessary visibility to safeguard OT systems with minimal disruption.

Similarly, organizations must not deploy OT/ICS patches on the same schedule because these systems are highly specialized. Patching OT and ICS systems requires careful consideration and validation due to their unique characteristics. These systems often use specialized hardware, software, and configurations that differ from regular IT environments. Patches designed for general IT systems might not be fully compatible with the specific technology stack of OT and ICS.

Thorough testing is crucial to ensure that patches do not inadvertently disrupt the stability or performance of these critical systems. Additionally, many industries have strict regulations and compliance requirements governing changes to OT and ICS environments, which must be adhered to. Some of the most well-known include: HIPAA, the Telecoms Security Act, and PCI DSS.

Considering the 24/7 operational nature of many OT and ICS systems, finding a suitable time for patching without causing significant disruptions can be challenging. Organizations need to plan meticulously to minimize any negative impact on production or services, considering planned downtime or outages to deploy OT/ICS patches effectively.

Organizations should also consider:

  • Network Segmentation: Implementing network segmentation involves dividing the ICS environment into isolated zones, limiting communication between systems. This segmentation prevents the lateral movement of attackers and contains potential breaches.
  • Strong Authentication: Enforcing robust authentication methods, such as multi-factor authentication, for all access points to OT/ICS components significantly reduces the risk of unauthorized access.
  • Anomaly Detection: Deploying advanced anomaly detection solutions enables real-time monitoring of OT/ICS networks, helping to detect abnormal behavior and potential cyber threats.
  • Air-Gapping Critical Systems: For particularly sensitive OT/ICS components, air-gapping involves physically isolating them from external networks, creating an extra layer of protection against remote cyberattacks.
  • Training and Awareness: Regularly conducting cybersecurity training for personnel operating OT/ICS systems help create a security-conscious culture and empowers them to identify and respond to potential threats.
  • Incident Response Planning: Developing comprehensive incident response plans outlines the actions to be taken during a cyber incident, facilitating a coordinated and swift response to minimize damages.
  • Vulnerability Rationalization: Conducting an OT consequence-based vulnerability rationalization study, based on Cyber PHA and alarm rationalization methodologies, focused on defining when to treat, tolerate, terminate, or transfer vulnerabilities will reduce the risk of downtime or disruptions.

Securing operational technology and industrial control systems is paramount in safeguarding critical infrastructure from cyber threats. As these systems continue to evolve and connect to broader networks, the challenges in maintaining their security become increasingly complex. Organizations can fortify their OT/ICS against potential cyberattacks and minimize the risks to essential operations by implementing network segmentation, strong authentication, anomaly detection, and regular patch management. Furthermore, combining technical solutions with ongoing training and a robust incident response plan will enhance the resilience of OT/ICS components and ensure the reliable and secure functioning of critical infrastructure in an ever-changing cybersecurity landscape.

ITEGRITI has deep experience across critical infrastructure cybersecurity programs, compliance, risk, and audit.  Contact us today to learn how we can leverage this experience to help you accomplish your cybersecurity goals.

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