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Adopting a holistic view of CNI security

25 June 20263 min read
Guest Insights
Adopting a holistic view of CNI security

Control, visibility, and resilience across modern interconnected supply chains

There’s – rightly – a heightened awareness of the numerous threats facing our nation’s Critical National Infrastructure (CNI), in light of the continued turbulence of the geopolitical landscape and the growing scale and sophistication of cyber-attacks. As a result, the National Cyber Security Centre (NCSC) has warned that far too many mission-critical systems are vulnerable to attack, with legacy infrastructure unable to keep pace with numerous evolving threats.

While one may assume that this is simply a question of updating legacy security systems and following current cyber best practice, the reality of the situation is more complex…

Critical infrastructure now spans physical sites, edge devices, public and private Cloud platforms, and – critically – a growing range of third-party providers, all of whom are intrinsic to maintaining a robust security posture. It doesn’t matter how strong an organisation’s own security ecosystem is if third parties who connect to its infrastructure lack the controls needed to operate to the same standards.

Bear in mind that when we talk about supply chain security, we’re no longer just talking about the physical security of goods in transit. The interconnected nature of modern, global infrastructure and ongoing convergence of IT and OT assets means that an increasing amount of data is transferred in and out of CNI systems (i.e. file IMPEX) than ever before – some of which is highly impactful on the performance of operational assets and may have high levels of sensitivity and confidentiality. And as AI increasingly establishes itself across supply chains for everything from data analysis to the automation of routine processes, concerns over the integrity, security, and sovereignty of CNI data will only increase.

Any point of transfer represents a potential ‘backdoor’ into CNI systems that bad actors will not hesitate to exploit. Indeed, we have already seen this in numerous high-profile incidents like the attack on the US Treasury in 2024, where hackers were able to access more than 3,000 internal documents via an IT contractor’s infrastructure, or the 2021 incident where the popular SolarWinds IT management platform was compromised, allowing bad actors to send administrator-level commands to users’ systems.

A robust cyber security posture must therefore accommodate all third-party providers and technology platforms, ensuring they are subject to the same standards as internal teams, with processes in place to ensure best practice is always followed. A standards-based approach is strongly advisable here, ideally based on the following frameworks and accreditations:

  • ISO 27001. The globally recognised standard for information security, which now includes a control around ‘Use of Cloud Services’.

  • ISO 9000. Five international standards around quality management and quality assurance.

  • NIS (2018). A baseline for the resilience of network and information systems, encompassing both physical and digital assets, strengthened by the new Cyber Resilience Bill.

  • Cyber Assessment Framework (CAF). The NCSC’s IGP self-assessment model for measuring, mitigating, and evidencing cyber risk and controls.

  • IEC-62443. A framework for assessing, identifying, and mitigating security vulnerabilities in critical infrastructure.

  • Cyber Assurance of Physical Security Systems (CAPSS). Assurance for physical security systems.

  • Cyber Essentials & Cyber Essentials Plus. Although these are UK-based accreditations, they are based on ISO 27001 and NIST 800 and so represent a robust baseline for cyber best practice (although this will need to be built on).

These standards provide a clear baseline for security best practice – both physical and digital – across all areas of a supply chain, and so should be considered when vetting potential third-party providers, with regular audits in place to ensure systems and processes remain fit for purpose.

This will very much be a journey rather than a one-off project, as IT/OT convergence increases, cyber threats evolve, and AI establishes itself across CNI workflows, but the result will be a new model of cyber-secured engineering that ensures dataflows remain secure, seamless, and fully sovereign at all times, optimising the delivery of mission-critical services across the UK.

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For more information on the CNI sector’s ongoing digital journey, our most recent report – Translating the new regulatory standards into a sustainable cyber strategy – is available for download here.