Targeted penetration tests secure industrial systems by revealing weaknesses early. This article outlines methods, requirements and best practices for machine builders, including CRA, IEC 62443 and safety aspects.
Attacks on industrial systems are increasing - with real consequences
Industrial IT and OT systems are increasingly the focus of targeted cyberattacks. According to the “X-Force Threat Intelligence Index 2025” by IBM (https://www.ibm.com/thought-leadership/institute-business-value/en-us/report/2025-threat-intelligence-index), the manufacturing sector was again the most affected worldwide - accounting for 40% of all recorded attacks. The particular risk in industrial environments is that a successful attack can not only compromise data but also influence physical processes.
It becomes critical especially when cyberattacks affect safety-related functions. If, for example, safety controllers, emergency stop chains or controlled machine movements are manipulated, there is an immediate danger to people and equipment. Additional risks include production downtime, quality problems or espionage. Consequences range from economic damage to liability risks for manufacturers and operators.
Regulatory pressure requires technical testing
Legislators have responded to these developments with the new Machinery Regulation, the Cyber Resilience Act (CRA) and the delegated regulation for the Radio Equipment Directive (RED DA). Manufacturers of machines and connected devices are obliged to assess cyber risks and implement technical protective measures - and to demonstrate their effectiveness. Security tests such as penetration tests are a central element of this evidence.
Relevant standards such as IEC 62443, EN 18031 or EN 50742 explicitly require that products and systems be tested for vulnerabilities - especially where risks to safety, availability or confidentiality exist.
Why penetration tests are indispensable in IIoT and OT environments
Security requirements for connected industrial systems are rising - not only because of regulatory demands, but also because technical dependencies between IT, OT and IIoT are increasing. Penetration tests help to uncover existing weaknesses in a targeted way before they lead to a real security incident.
They make a concrete contribution to securing critical infrastructures, reducing risk and strengthening product responsibility. Whether an industrial control panel, a connected device or an embedded component: tests under realistic conditions show how robust the product really is against targeted attacks.
Particularly important is the focus on faults that were overlooked during development or not detected in validation tests - for example insufficient authentication mechanisms, missing hardening or insecure firmware communication. A professionally conducted penetration test makes these weaknesses transparent and provides actionable recommendations.
OT penetration tests require special know-how
Planning an OT or IIoT penetration test requires close coordination with development, engineering, product management and, if applicable, safety teams. The aim is to analyse relevant systems in a targeted way without endangering the function of safety-critical or production-near components.
Crucial is a clear definition of the test scope (scoping): which components should be tested? Which scenarios are realistic? Which interfaces are particularly critical? Equally important: the test period must be coordinated with the product team so that potential impacts are technically secured in advance - e.g. through tests in laboratory or reference environments.
Integrating a simplified threat model as part of the scoping helps to systematically identify attack paths and define realistic test goals - not as a blanket “black box”, but product-near, focused and comprehensible.
Typical procedure of an industrial penetration test
Penetration tests in industrial environments differ fundamentally from classic IT tests. The goal is not primarily to demonstrate maximum damage potential but to systematically find security-relevant weaknesses under realistic conditions - especially those not detected during development or testing. The focus is on targeted lab tests and a structured root-cause and risk analysis.
- Scoping with scenarios and threat modeling
At the beginning, concrete test goals, assets and attack vectors are defined together with the manufacturer. Simplified threat models that are oriented to realistic attack scenarios are used - for example remote access to a machine, sabotage via maintenance interfaces or data exfiltration via cloud gateways. The scope is defined so that safety-relevant components and functions are the focus, such as controllers, communication interfaces or HMI systems.
- Laboratory-based execution
The actual test is carried out in an isolated environment - either on a test device, a laboratory configuration or a digital twin. Here, security-relevant weaknesses can be analysed in a targeted manner without endangering the real production system. The focus is on weaknesses in authentication, access control, communication security or logic errors in the implementation of safety-critical functions.
- Analysis of the findings: root cause and impact
Unlike classic penetration tests, the emphasis is not only on discovery but also on understanding the cause. For each finding a structured root cause analysis is carried out: was it an architectural error? An implementation mistake? A configuration deficiency? In addition, the concrete impact is systematically analysed: which functions would be affected? Would safety be impacted? How large is the realistic risk in case of misuse?
- Risk-based prioritization and improving development
The identified weaknesses are assessed and prioritized according to their criticality. The final report contains not only technical details and reproduction instructions but concrete recommendations for remediation - with a focus on sustainably improving development and testing processes. The goal is not only to close the found issues but also to avoid similar errors in the future.
Selection criteria: what qualifies providers of industrial penetration tests
The quality of an OT or IIoT penetration test depends on the expertise of the test team. Unlike classic IT pentests, technical tool knowledge alone is not enough. What matters is a deep understanding of industrial systems, development processes and regulatory requirements.
A qualified provider brings the following competencies:
- Experience with industrial controllers, communication protocols and security architectures - e.g. handling PLCs, HMIs, fieldbus systems, proprietary protocols or safety-oriented control technology.
- Competence in test design and execution under lab conditions, to examine weaknesses in a targeted and controlled way - without risk to ongoing operations.
- Ability to perform root cause analysis, i.e. a structured investigation of the causes of identified weaknesses - for example in architecture, implementation or configuration.
- Understanding of functional safety and safety-related requirements, to correctly assess interactions between security and safety.
- Experience with regulatory requirements such as the Cyber Resilience Act, the Machinery Regulation, the Radio Equipment Directive and relevant standards like IEC 62443, EN 18031 or EN 50742.
Professional providers not only deliver a list of technical vulnerabilities but clearly show where gaps exist in development or testing - and how to avoid them in the future.
Best practices: how companies get the most out of a pentest
To ensure a penetration test in industrial environments is more than a one-off proof, it should be embedded in product development, quality assurance and security strategy. The aim is not only to close individual weaknesses but to structurally improve product security.
- Plan tests early
Penetration tests should not take place only at the end of a project. Especially for new developments or fundamental changes (e.g. new communication modules, remote interfaces, cloud integration), a test before placing on the market is recommended - ideally in parallel with internal verification to uncover unnoticed weaknesses. - Use laboratory environments
For OT systems, a controlled test environment with realistic components is recommended - e.g. labs with typical controllers, IIoT gateways or simulated machine processes. This allows identification of security-relevant weaknesses without endangering productive systems. - Feed results back into development processes
Insights from the test should flow into lessons learned, secure coding guidelines or the architectural design. For recurring weaknesses, it is worth supplementing internal test and approval processes. - Assess and prioritize risks comprehensibly
A simple “vulnerability listing” is not sufficient. Test results must be evaluated with regard to safety, availability, possibilities for manipulation and regulatory relevance - in a way that is comprehensible for technical decision-makers and management. - Continuity instead of a one-off action
Even with limited resources: penetration tests should be carried out regularly - e.g. annually or risk-based by product groups. As maturity grows, tests can be integrated into internal test procedures (e.g. integration tests) or used as a basis for certifications.
Conclusion: play it safe when it comes to security
In industrial environments, penetration tests are much more than a mere test procedure - they are a central instrument for quality assurance of safety-relevant systems. Used correctly, they not only uncover weaknesses but also make it possible to understand their causes and to improve development processes in a targeted way.
Especially in the context of increasing connectivity, growing regulatory requirements (e.g. CRA, Machinery Regulation) and the critical importance of safety functions, a structured, risk-based and technically well-founded testing approach is essential. Those who test OT and IIoT systems deliberately protect not only systems and data but also operations, reputation and market access.
Want to test your products we can help
Secuvi is specialized in penetration tests in industrial environments. We test OT systems, IIoT components and connected machine functions - under laboratory conditions, risk-based and with a focus on sustainable improvement. Our testers combine deep technical understanding with regulatory know-how and many years of experience in product development, testing practice and implementation of standards (e.g. IEC 62443, EN 18031, CRA).
Whether a targeted lab test, continuous test support or specific preparation for audits - we help you systematically identify security gaps, analyse root causes and strengthen your development processes.
Contact us, if you:
- plan a penetration test for a specific product,
- need to meet regulatory requirements (e.g. CRA or Machinery Regulation),
- want to validate or improve your internal testing procedure,
- or are looking to get started with systematic security testing.
We look forward to the exchange - and will help you make security a strength of your products.