IT and OT Convergence: Opportunities and Security Risks for Private Networks

Posted by on

The worlds of Information Technology and Operational Technology have been moving closer together for several decades. What once started as completely separate domains has gradually converged, creating opportunities for efficiency and integration but also introducing significant new risks.

Operational Technology refers to the systems that control physical processes in factories, utilities, transport, and other industrial environments. These include motors, pumps, sensors, programmable logic controllers and supervisory control systems. Historically, these devices were isolated from corporate networks and operated through proprietary protocols. A technician often had to be physically present to make adjustments or monitor performance.

Over time the desire for automation, cost reduction and remote visibility encouraged industries to adopt shared communication standards. Field buses such as Modbus appeared, allowing multiple devices to be controlled over a common medium. Later, with the rise of Ethernet and the broad adoption of TCP IP, industrial systems began to take advantage of the same networking technologies used in offices and data centres. The result was a wave of IT and OT convergence, with industrial Ethernet becoming a widespread standard.

The opportunities of this convergence are clear. Using IT networking protocols in industrial environments makes integration with enterprise systems easier and cheaper. It becomes possible to deploy monitoring tools, collect operational data, and manage processes with the same skill sets used in corporate IT. When combined with private networks such as LTE and 5G, organisations can securely connect machines, sensors and controllers across wide areas, enabling flexibility that was previously out of reach.

However, the security risks are equally apparent. Many OT devices were originally designed with the assumption that they would be isolated and only accessible within a controlled environment. As a result, they often lack authentication, encryption or even basic resilience against network threats. When these systems are connected to IP networks, especially if exposed beyond the factory floor, they can be reached and manipulated remotely. In some cases, critical infrastructure devices have been found accessible on the public internet with no safeguards in place. The consequences are not theoretical: fuel gauges at petrol stations, programmable logic controllers in utilities, and power distribution systems have all been shown to respond to unauthenticated network probes.

One technical complication is that many OT devices do not natively speak IP. Protocols such as Modbus, DNP3 and Ethernet IP often sit behind gateways or protocol adapters that translate between legacy buses and modern networks. While this makes them easier to integrate into an IP environment, it also creates blind spots. Standard network scans may only reveal the gateway rather than the devices behind it. Specialised discovery techniques are required to query these devices across protocol boundaries, often by using specific function codes or attributes defined in the protocol. Without this kind of deep discovery, organisations cannot build an accurate asset inventory, which makes security monitoring and incident response far more difficult.

Consider Modbus as an example. Originally developed in 1979, it remains one of the most widely used industrial protocols. It was designed for simplicity, with basic read and write functions and little thought for security. When Modbus was later carried over TCP IP networks, the original protocol was embedded almost unchanged. This meant that devices which once could only be accessed via serial connections on the factory floor suddenly became reachable across IP networks. A malicious actor able to reach a Modbus device could issue read or write commands directly to registers and coils, potentially altering processes with no authentication or validation. This illustrates how a protocol built for a closed environment becomes a liability once integrated into a converged network.

For operators deploying private networks, this creates both a challenge and an opportunity. A private cellular system can provide strong isolation from the public internet, dedicated security controls and reliable connectivity across demanding industrial environments. At the same time, the responsibility falls on network architects to ensure that OT devices are not simply transplanted into a new connectivity layer without addressing fundamental weaknesses. Visibility, device discovery and proper segmentation are essential to prevent vulnerabilities from travelling across the converged environment.

The convergence of IT and OT is not just a technical shift but a cultural one. Engineers and security teams must work together to understand the unique requirements of industrial systems and the realities of modern networking. Private networks can be a powerful enabler of this transformation, but only if deployed with a clear understanding of both the opportunities and the risks.

To explore these issues in more depth, the following presentation by Rob King, Director of Applied Research at runZero delivered at DEF CON 33 provides an excellent walk-through of OT protocols, gateways, and discovery techniques that highlight both the possibilities and the pitfalls of convergence.

Related Posts: 

Comments

Post a Comment