Firmware updates with OPC UA: Secure. Smart. Standardized.
Update System Upgrade Software version technology concept on virtual screen.
The EU Cyber Resilience Act (CRA) places greater emphasis on the security of industrial systems, such as programmable logic controllers. The aim of the new regulation is not only to prevent security vulnerabilities, but also to ensure that known weaknesses are consistently fixed. The CRA is not a non-binding recommendation, but a binding legal requirement for manufacturers of such devices. Non-compliance can have both security-related and legal consequences. The implications for companies are clear: firmware updates can no longer be postponed. Only regular and timely updates can close known security gaps. At the same time, they ensure compliance with legal requirements.
Why firmware updates are challenging in industrial environments
In everyday life, software updates have long become routine. Smartphones, laptops, and smart home devices usually receive their updates automatically over the Internet (Over-the-Air, OTA). The updates are downloaded and installed directly from the manufacturer without any manual action required from users.
In industrial environments, the situation is very different. Control systems are often located in remote or hard-to-reach areas, which makes physical access difficult. In so-called air-gapped infrastructures, where production networks are deliberately isolated from external networks, an OTA approach is not feasible. Even in safety-critical facilities, network access is often heavily restricted to prevent tampering or unauthorized access. In such cases, firmware updates still have to be installed using physical data carriers.
But even when the technical conditions are in place, there are additional practical challenges. Many manufacturers use their own update mechanisms and proprietary tools. For maintenance personnel, this means considerable effort: they must select the right tool for each device, follow the instructions, and check compatibility.
The need for a unified, secure update mechanism
The ability to perform security-relevant firmware updates remotely is crucial for cyber resilience and efficient maintenance. To simplify maintenance independently of the manufacturer, a standardized update mechanism is required. Operators should be able to decide when and how updates are installed, for example during scheduled maintenance windows.
OPC UA offers a solution here. This technology is widely used, established, and accepted in the OT world. Its modular architecture makes it an ideal interface for secure, standardized firmware updates.
OPC UA as a basis for cross-vendor updates
An open standard for implementing updates across different manufacturers already exists with the interface defined in OPC UA Specification Part 100. We tested this approach using a WAGO PFC200. The firmware for the PFC200 is provided as a Board Support Package and can be customized and extended by developers.
For this purpose, we developed our own OPC UA server based on open-source libraries, which provides the update interface. Internally, the server uses the device's native update procedures to carry out the installation.
The OPC UA standard defines several ways to transfer the update file to the device. In our case, we used direct file system access. Alternatively, the file can be cached or transmitted via streaming, allowing the update mechanism to be applied flexibly to other device classes.
Future-proof updates with open standards
Thanks to the generic OPC UA interface, numerous possibilities exist for client-side extensions, ranging from simple scripts to complex applications that implement a company-specific update policy. The system remains secure, as it relies on the proven security mechanisms of OPC UA.
We support you in implementing firmware updates securely, smart, and across manufacturers.
