The Cybersecurity Gap in Legacy Building Systems—

and How to Bridge It

In today’s interconnected world, the security of building systems is more critical than ever. However, many facilities still rely on legacy building systems—HVAC, lighting, access control, and other automation technologies—that were designed decades ago without cybersecurity in mind. These systems often operate on outdated protocols, lack encryption, and may even have unsecured internet connections, making them vulnerable to cyber threats that can compromise safety, efficiency, and privacy.

Modernizing these legacy systems may seem daunting, with concerns about high costs, heavy downtime, and complex replacements. Yet, addressing these vulnerabilities is essential to protect critical infrastructure and ensure the resilience of building operations.

Understanding the Challenges of Legacy Building Systems

Legacy building systems were designed and deployed before cybersecurity became a top priority. These systems were built with the assumption that they would operate within closed networks, isolated from the external world. However, the rapid integration of IT and OT systems has exposed these legacy devices to a range of cyber threats. Many OT systems, such as building automation, were designed and deployed before security concerns became a top priority. These systems were built with the assumption that they would operate within closed networks, isolated from the external world. However, the rapid integration of IT and OT systems has exposed these legacy devices to a range of cyber threats.

Legacy devices often lack essential security features, such as encryption, authentication protocols, and regular security updates. These vulnerabilities create significant security gaps, leaving automation control systems susceptible to attacks. Additionally, the long lifecycles of these devices make it challenging or impractical to implement timely security patches and updates, further increasing the risk.

The Importance of Upgrading Legacy Systems

Modernizing legacy systems is not just about enhancing security; it’s about ensuring the continued functionality and efficiency of building operations. Upgrading these systems allows organizations to:

• Improve Security: Implementing modern security protocols and practices helps protect against evolving cyber threats.
• Enhance Operational Efficiency: Upgraded systems can lead to improved performance and reduced downtime. ref
• Ensure Compliance: Meeting regulatory requirements becomes more manageable with updated systems.
• Future-Proof Operations: Modern systems are better equipped to integrate with emerging technologies and adapt to future needs.

According to experts, including those cited in a recent Forbes Tech Council article, upgrading legacy systems isn’t just a best practice; it’s becoming a regulatory and operational necessity. forbes.com

Implementing Zero Trust Security in Legacy Systems

Implementing Zero Trust Security in legacy OT devices, systems, and equipment requires balancing modern security principles with the limitations of aging infrastructure.

There are three potential options to consider for adding device-level zero trust:

Method	Pros	Cons
Device Replacement	New equipment with modern security	Expensive; Zero Trust not available in all equipment or for all protocols
Software-Defined Networking	Zero Trust enforced through whitelist/blacklist policies	Incapable of data encryption for traffic from existing edge devices – traffic type and data still plaintext
Security Overlay	Zero Trust enforced from security appliances; Easy to deploy; Transparent to network devices; No changes to existing network or devices; End-to-end encryption	Security appliance needed for each IP device

Network monitoring solutions that detect anomalies are not capable of providing zero trust or encrypting data traffic, and were intentionally excluded from the table above.

Implementing a security overlay approach can be an effective way to add Zero Trust security to legacy systems without the need for extensive replacements or disruptions. This approach involves deploying security appliances that enforce Zero Trust principles, ensuring that all devices within the network are authenticated and authorized before granting access.

Benefits of Zero Trust for OT Cybersecurity

Implementing a Zero Trust model in OT environments offers several benefits:

• Improved Security: A Zero Trust model assumes that all network traffic is untrusted and requires authentication and authorization before granting access. This means that even if an attacker gains access to the network, they cannot move laterally or escalate privileges without being detected.
• Enhanced Visibility and Control: Zero Trust provides comprehensive visibility into network traffic and user activities, enabling organizations to monitor and control access to critical systems effectively.
• Reduced Attack Surface: By enforcing strict access controls and continuously verifying trust, Zero Trust minimizes the potential entry points for cyberattacks, reducing the overall attack surface.
• Regulatory Compliance: Many industries have stringent regulatory requirements for securing critical infrastructure. Zero Trust helps organizations meet these compliance standards by implementing robust security controls and demonstrating a proactive security posture.veridify.com

Overcoming the Challenges of Legacy System Modernization

While upgrading legacy systems is essential, it can be challenging due to factors such as cost, downtime, and the complexity of replacing outdated equipment. However, there are strategies to mitigate these challenges:

• Prioritize Critical Systems: Focus on upgrading the most critical systems first to minimize potential risks and disruptions.
• Phased Implementation: Implement upgrades in phases to spread out costs and reduce downtime.
• Leverage Existing Infrastructure: Where possible, integrate new security measures with existing systems to avoid complete replacements.
• Seek Expert Guidance: Consult with cybersecurity professionals to develop a tailored plan that addresses specific needs and challenges.

Modernizing these legacy systems may seem daunting, with many building managers fearing high costs, heavy downtime, and complex replacements. Thankfully, there’s a smarter solution.

Introducing KMC Dome™

KMC Dome is designed to retrofit and secure both new and existing devices without the need for expensive overhauls or disruptions to your building’s daily operations. Its innovative approach integrates seamlessly with your existing infrastructure, bridging the gap between outdated systems and cutting-edge Zero Trust cybersecurity principles. With KMC Dome, you get peace of mind knowing your building is protected while avoiding the headaches that traditional upgrades can bring.

KMC Dome leverages Zero Trust security principles, meaning every layer of your system is continually verified and protected. Whether it’s defending your building automation systems against cyberattacks or streamlining your operations for optimal performance, Dome is your first line of defense. And the best part? It’s designed with flexibility in mind, making it ideal for both legacy systems and new infrastructure. Imagine upgrading your systems to a modern, secure solution without the headaches of starting over from scratch. With KMC Dome, implementation is seamless. Our expert team works closely with you to ensure minimal disruption to daily operations. Not only do you save precious time, but you also get a solution tailored to meet the unique needs of your facility.

The Stakes for Building Security Have Never Been Higher

Cyber threats are becoming more sophisticated, taking advantage of vulnerabilities many organizations don’t even realize they have. By proactively addressing these issues now, you’ll save countless time, money, and stress in the future.

Don’t wait until vulnerabilities become liabilities. Take the first step toward securing your building today. Watch our full product demo to see KMC Dome in action and schedule a consultation to learn how we can safeguard your systems.

Together, we can create secure, efficient environments that you can count on every day. When it comes to your building’s safety, don’t settle for less than the best. Choose KMC Dome and experience the confidence of uncompromised protection. Don’t wait until a breach forces you to act. Secure your business future today. Contact us to learn more about KMC Dome and Zero Trust architecture and safeguard your building systems for years to come. 

References:

Zero Trust Security for Legacy OT Devices – Veridify Security

2025 Cybersecurity Agenda: Upgrading Legacy Systems

Addressing Cybersecurity Challenges in Legacy Systems with IEC 62443