IT and OT: A Tale of Interdependencies

In years gone by, Information Technology (IT) and Operational Technology (OT) were siloed entities with minimal effect on one another. Today, IT and OT exist in symbiosis. As such, modern cybersecurity threats transcend traditional boundaries; an attack on IT systems can bring OT to its knees, and vice versa. This interdependence has increased the need for adequately zoned architecture – the Purdue Model, for example – and Zero Trust architecture.

This post explores how IT and OT systems are connected, how this affects what threats organizations face, and how organizations can protect themselves.

The Changing Landscape: From Air-Gapped to Connected Environments

The OT landscape has significantly transformed from air-gapped environments to connected ones. This shift has brought about profound changes in both opportunities and challenges.

Traditionally, OT systems operated in isolated, air-gapped environments. These environments were physically and logically separated from external networks like the Internet. The primary objective of air-gapping was to protect critical infrastructure from cyber threats by minimizing the attack surface and reducing the potential for remote exploitation.

However, the demands of digital transformation, data-driven decision-making, and operational efficiency have driven industries toward connected environments. This connectivity enables seamless IT and OT systems integration, facilitating real-time data exchange, remote monitoring, and enhanced control over industrial processes. Several factors have contributed to this transformation:

Advancements in Communication Technologies – The proliferation of wired and wireless communication technologies has made it easier and more cost-effective to establish connections between OT systems and external networks. Ethernet, Wi-Fi, cellular networks, and other technologies provide the means for secure data transmission and remote access.
Industry 4.0 and the Internet of Things (IoT) – The emergence of Industry 4.0 concepts and the widespread adoption of IoT devices have accelerated the connectivity of OT systems. IoT devices, sensors, and actuators embedded within industrial environments enable data collection, analysis, and automation, improving operational efficiency and productivity.
Remote Access and Monitoring – Remote access capabilities have become crucial for efficiently managing OT systems. With connected environments, operators and maintenance personnel can remotely access and monitor industrial assets, troubleshoot issues, and perform maintenance tasks without physically being present at the site.

Impacts of IT Dependencies on OT Systems

While the increased connectivity between IT and OT systems has facilitated operational efficiencies and innovations, it has also brought about new threats that present significant challenges for industrial organizations. Those threats include:

Increased Vulnerability – Introducing IT assets into OT environments means adopting commonly used operating systems, applications, and protocols, which are often more prone to known vulnerabilities; this increases the risk of malware infections, unauthorized access, data breaches, and exploitation of vulnerabilities within OT systems.
Supply Chain Risks – IT and OT systems often rely on a complex web of suppliers and vendors. A compromise in the IT infrastructure or supply chain can have cascading effects on the OT systems, potentially leading to disruptions in critical operations.
Operational Disruption – If IT systems supporting OT operations experience downtime, it can directly impact the availability, reliability, and safety of OT processes.

The Value of Identifying and Controlling Interrelationships

Organizations must identify and control the relationships between IT and OT systems to address the challenges above. Doing so will grant them:

Enhanced Visibility – Understanding the dependencies between IT and OT systems provides better visibility into potential cyber risks and vulnerabilities. This knowledge allows organizations to prioritize security efforts and implement appropriate controls to protect critical assets.
Rapid Incident Response – Organizations can establish effective incident response procedures encompassing IT and OT domains by recognizing interdependencies. This integrated approach enables faster detection, containment, and recovery from cybersecurity incidents.
Comprehensive Risk Management – Identifying interrelationships allows organizations to conduct thorough risk assessments that encompass both IT and OT domains. This holistic approach enables the development of robust risk mitigation strategies that address the entire ecosystem.

The Need for a Zoned Security Architecture and Zero Trust Mindset

Organizations should adopt a zoned security architecture like the Purdue Model to safeguard IT and OT environments effectively. This model segregates networks based on their criticality and function, limiting the lateral movement of threats between IT and OT domains. A Zero Trust mindset, which assumes no inherent trust within or between systems, is crucial in today’s threat landscape. Implementing Zero Trust principles, such as strong authentication, access controls, and continuous monitoring, helps mitigate the risk of unauthorized access and lateral movement within interconnected systems.

The interdependencies between IT and OT systems have introduced both advantages and challenges. While connectivity and digital transformation bring increased efficiencies to OT operations, they expose critical infrastructure to new cybersecurity threats. Understanding and controlling these interrelationships through a properly zoned security architecture and a Zero Trust mindset is essential for protecting OT systems from evolving cyber risks. By acknowledging the impacts of IT dependencies and implementing appropriate security measures, organizations can secure their operations and maintain the resilience of their critical infrastructure.

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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