Sometimes, the weakest links in an organisation’s security chain aren’t found in the fancy technologies or advanced analytics but in the very blueprint of the infrastructure itself. Poorly designed networks, data centres, and system architectures can create latent vulnerabilities that attackers are more than willing to exploit.
The Foundation Matters
Infrastructure forms the foundation upon which all security controls sit. If the core design is flawed—e.g., flat network architecture with no segmentation—then even the best security tools struggle to contain an attack. Cybercriminals often rely on lateral movement within a victim’s network, exploiting a lack of boundaries. Once inside, they can easily traverse the environment, seeking valuable data or critical systems.
Common Design Flaws
- Insufficient Segmentation: A flat network design allows attackers free rein once they breach the perimeter. Network segmentation limits the spread of malware or unauthorised access.
- Weak Remote Access: Many organisations allow remote access without robust authentication or segmentation. This can become a direct entry point for attackers.
- Inadequate Redundancy: Lack of redundancy in core systems leads to single points of failure. During an attack, critical services might be taken offline if they rely on a single node.
- Legacy Systems: Outdated operating systems or hardware can’t support modern security controls and may contain unpatched vulnerabilities.
The Importance of Architecture Reviews
Regular architectural reviews help highlight whether your infrastructure has kept pace with evolving needs and threats. These reviews should cover everything from physical layout (such as data centre access) to logical design (such as virtual networks). If the environment has grown organically over time, you may have accumulated hidden dependencies and shortcuts that now pose security risks.
Linking Infrastructure to the Kill Chain
Infrastructure design influences nearly every stage of the kill chain. During reconnaissance, attackers probe the network to gauge its complexity and discover weak points. In the delivery and exploitation phases, a poorly segmented or insecure network can grant them easy access to critical systems. Finally, robust design with internal monitoring can detect lateral movement or data exfiltration attempts. An incomplete or outdated infrastructure approach can leave blind spots at each of these stages.
Modern Best Practices
- Zero-Trust Approach: Instead of assuming trust inside your perimeter, treat every asset and user with suspicion by implementing strict access controls.
- Micro-Segmentation: Move beyond basic segmentation to segment smaller “pods” of workloads or devices, minimising the damage a breach can inflict.
- Containerisation and Virtualisation: Isolate applications in containers or virtual machines for improved security. This approach makes it more difficult for attackers to move laterally.
- Disaster Recovery and Resilience: Ensure redundancy and failover for critical services so that a successful attack on one system won’t cripple your entire organisation.
Ongoing Adaptation
Infrastructure design isn’t a one-off exercise. It should adapt to shifts in technology—such as the move to the cloud or widespread remote work – and keep pace with new threats. Periodic penetration tests can uncover structural weaknesses, while threat modelling exercises can illustrate how attackers might attempt to breach your defences.
A strong security posture starts with a solid infrastructure foundation. By investing time and resources into thoughtful network design, you limit attackers’ ability to manoeuvre and cause damage. Neglecting this foundational layer, however, can render even the most advanced security solutions far less effective. In our final blog of this series, we’ll discuss how to bring everything together – touching on responsibilities, supplier demarcation, and actionable steps to close the most critical gaps.