CISA’s OT Cybersecurity: Asset Inventory Essentials

When you think about protecting critical infrastructure, pipelines, power grids, or water treatment facilities, the first question isn’t how to defend them, but what exactly are we defending? That’s the challenge The Cybersecurity & Infrastructure Security Agency or the CISA tackled in its August 13th 2025 guidance on OT cybersecurity. 

In today’s interconnected world, attackers don’t just target IT networks; they’re increasingly probing operational technology, the systems that keep our industries running. Yet many owners and operators still struggle with a basic but vital step: building a clear, accurate inventory of their assets. Without that visibility, defenses are built on guesswork, and guesswork is a dangerous foundation when lives, economies, and national security are at stake.

Contact Digital Revolution

• "X" Post (formerly Twitter) us at @DigitalRevJim
• Email: Jim@JimKunkle.com

Follow Digital Revolution On:

• YouTube @ www.YouTube.com/@Digital_Revolution
• Instagram @ https://www.instagram.com/digitalrevolutionwithjimkunkle/
• X (formerly Twitter) @ https://twitter.com/digitalrevjim
• LinkedIn @ https://www.linkedin.com/groups/14354158/

If you found value from listening to this audio release, please add a rating and a review comment. Ratings and review comments on all podcasting platforms helps me improve the quality and value of the content coming from Digital Revolution.

I greatly appreciate your support of the revolution!

Transcript

When you think about protecting critical infrastructure, pipelines, power grids, or water treatment facilities, the first question isn’t how to defend them, but what exactly are we defending? That’s the challenge The Cybersecurity & Infrastructure Security Agency or the CISA tackled in its August 13th guidance on OT cybersecurity. In today’s interconnected world, attackers don’t just target IT networks; they’re increasingly probing operational technology, the systems that keep our industries running. Yet many owners and operators still struggle with a basic but vital step: building a clear, accurate inventory of their assets. Without that visibility, defenses are built on guesswork, and guesswork is a dangerous foundation when lives, economies, and national security are at stake.  

This episode dives into why the CISA’s new framework matters right now. We’ll explore how asset inventories are more than spreadsheets, they’re the blueprint for resilience. Imagine trying to respond to a cyber incident without knowing which devices are connected, which systems are critical, or which vendors supplied the software. That’s like fighting a fire blindfolded. By setting a standard for OT asset taxonomy and inventory management, CISA is giving owners and operators the tools to see clearly, prioritize effectively, and act decisively. And in a world where downtime can ripple across entire supply chains, that clarity isn’t just technical, it’s strategic.  

Context & Background

Operational Technology, or OT, refers to the hardware and software systems that directly monitor and control physical processes, everything from pipeline valves and power grid substations to water treatment sensors and factory automation. Unlike traditional IT networks, which focus on data and business operations, OT environments are tied to the real world. A cyber incident in OT doesn’t just mean lost data; it can mean disrupted energy supplies, contaminated water, or halted manufacturing lines. That’s why visibility into these systems is so critical. Yet historically, many operators have struggled to maintain accurate inventories of their OT assets. Legacy equipment, vendor diversity, and siloed maintenance practices often leave businesses with blind spots, making it difficult to know what’s connected, what’s vulnerable, and what’s most critical.  

CISA’s August 13th guidance arrives at a pivotal moment. Cyber threats targeting OT have grown more sophisticated, with adversaries exploiting gaps in asset awareness to gain footholds in critical infrastructure. Past incidents have shown that when operators don’t have a clear picture of their environment, response times slow and risks multiply. By establishing a standardized approach to asset inventory and taxonomy, CISA is helping owners and operators move from reactive firefighting to proactive resilience. This context sets the stage for why the guidance matters: it’s not just about compliance or documentation, but about building the foundation for defending the systems that keep society running.  

Core Guidance Highlights

At the heart of CISA’s August 13th 2025 guidance is a clear, repeatable process for building and maintaining an OT asset inventory. The first step is defining the scope, knowing which systems, environments, and processes fall under “operational technology.” This isn’t just about listing equipment; it’s about drawing boundaries so operators can focus on what truly matters to their mission. Once scope is set, the guidance emphasizes asset identification: cataloging every piece of hardware, software, and system that plays a role in operations. From controllers and sensors to specialized applications, visibility begins with a comprehensive list. 

But CISA goes further than just “making a list.” The guidance calls for collecting detailed attributes for each asset, vendor, version, function, and criticality. This transforms the inventory into a living dataset that can be used for risk management and incident response. The next step is taxonomy creation, where assets are organized into categories that reflect their operational importance. By grouping assets this way, operators can quickly see which systems are most critical, which are most vulnerable, and where to prioritize defenses. Finally, the guidance stresses lifecycle management: inventories must be kept current, integrated with maintenance and reliability programs, and continuously improved. In short, this isn’t a one-time project, it’s a foundational discipline for resilience in OT cybersecurity.  

Sector-Specific Examples

When we talk about OT asset inventories, the real power of CISA’s guidance comes alive in sector-specific contexts. Take oil and gas, for example. Pipeline operators rely on sensors, controllers, and SCADA systems to monitor flow and pressure across vast networks. Without a clear taxonomy, it’s easy to overlook older devices or vendor-specific software that may still be connected to critical systems. By applying CISA’s framework, operators can categorize assets by function, such as monitoring, control, or safety, and quickly identify which ones are most critical to pipeline integrity. This not only strengthens cybersecurity but also supports compliance with industry regulations and reliability standards.  

In the electricity sector, the stakes are equally high. Grid operators manage substations, transformers, and control systems that keep power flowing to millions of customers. An accurate inventory helps them distinguish between assets that are essential for real-time grid stability versus those that support monitoring or reporting. For example, knowing which devices are directly tied to load balancing or frequency regulation allows operators to prioritize defenses where disruption would have the greatest impact. Similarly, in water and wastewater systems, inventories can highlight treatment plant instrumentation, chemical dosing systems, and pumping stations. These are often overlooked in cybersecurity planning, yet they’re vital for public health and safety. By tailoring taxonomies to each sector, CISA’s guidance ensures that owners and operators aren’t just building lists, they’re building strategic maps of their most critical assets.  

Strategic Benefits

One of the biggest advantages of adopting CISA’s asset inventory guidance is the ability to respond faster and smarter to incidents. When operators know exactly which devices are connected, which systems are critical, and which vendors supplied them, they can immediately pinpoint where a cyber event is unfolding. That visibility reduces downtime, limits the spread of an attack, and ensures that recovery efforts are targeted rather than scattershot. In industries where minutes of disruption can ripple across supply chains or communities, this speed is not just technical, it’s strategic.  

Another benefit is prioritized risk management. By organizing assets into a taxonomy, operators can see which systems are most vital to operations and which are most vulnerable to exploitation. This allows them to allocate resources where they matter most, rather than spreading defenses too thin. It also strengthens compliance with regulatory frameworks and industry standards, demonstrating to stakeholders and regulators that the business is proactively managing its risks. Beyond compliance, inventories support long-term resilience by integrating cybersecurity into reliability and maintenance programs. Instead of treating asset visibility as a one-off project, businesses can embed it into their operational culture, aligning cybersecurity with digital transformation and sustainability goals. In short, inventories become more than lists, they become strategic maps for resilience, trust, and continuity.  

Challenges and Realities

While CISA’s guidance lays out a clear roadmap, the reality of implementing an OT asset inventory is far from simple. Many operators face resource constraints, especially in smaller utilities or mid-sized industrial firms where budgets and staff are stretched thin. Building and maintaining a comprehensive inventory requires not only technical tools but also dedicated personnel who understand both OT and cybersecurity. For businesses already juggling compliance, maintenance, and operational demands, adding another layer of responsibility can feel overwhelming. Legacy systems compound the issue, older equipment may lack modern monitoring capabilities, making it difficult to capture accurate data without costly retrofits or manual processes.  

Another challenge lies in workforce development and training. OT environments often involve staff who are experts in engineering and operations but may not have deep cybersecurity backgrounds. Bridging that gap requires investment in training and cultural change, ensuring that asset visibility is seen not as an IT exercise but as a core operational discipline. Additionally, vendor diversity creates complexity: operators may rely on dozens of suppliers, each with different standards, software versions, and maintenance practices. Harmonizing that into a single taxonomy is no small feat. Finally, there’s the reality that inventories are never “finished.” They must be continuously updated as systems evolve, new assets are added, and vulnerabilities emerge. For many businesses, the challenge isn’t starting an inventory, it’s sustaining it as a living, breathing foundation for resilience.  

Actionable Takeaways

The most important message from CISA’s guidance is that building an OT asset inventory doesn’t have to be overwhelming, it can start small and grow over time. Owners and operators should begin by establishing a baseline inventory of their most critical systems. Even a simple list of controllers, sensors, and software versions provides a foundation for visibility. From there, businesses can expand the scope, layering in attributes like vendor details, patch levels, and operational criticality. The key is to treat this as a living process, not a one-off project. By committing to incremental progress, operators can steadily improve their resilience without waiting for a “perfect” inventory to be completed.  

Another takeaway is the importance of leveraging CISA’s taxonomy templates as a guide. These sector-specific examples, covering oil and gas, electricity, and water/wastewater, offer a practical starting point for categorizing assets by function and importance. Operators should adapt these templates to their unique environments, ensuring that inventories reflect the realities of their operations. Finally, businesses should integrate asset visibility into their maintenance and reliability programs, so updates happen naturally as systems evolve. This ensures inventories remain current and actionable. By embedding inventory management into daily operations, owners and operators can transform visibility from a compliance checkbox into a strategic advantage, strengthening both cybersecurity and operational continuity.  

As we wrap up this discussion on CISA’s Foundations for OT Cybersecurity: Asset Inventory Guidance, the central theme is clear: visibility is power. Without a reliable inventory, owners and operators are essentially flying blind in environments where every asset plays a role in safety, reliability, and resilience. By adopting CISA’s framework, businesses can move from reactive firefighting to proactive defense, ensuring they know not only what they have but how it fits into the bigger picture of operational continuity. This guidance isn’t just about compliance, it’s about building confidence in the systems that keep our critical infrastructure running.  

For listeners, the takeaway is straightforward: start where you are, use the tools and templates provided, and commit to making asset visibility a living discipline. Whether you’re in oil and gas, electricity, or water systems, the principles apply across the board. Cyber threats will continue to evolve, but with a strong inventory and taxonomy, operators can respond with clarity and precision. 

Thank You for joining the Digital Revolution in unraveling this fascinating topic. Be sure to stay tuned for more episodes where we dive deep into the latest innovations and challenges in the digital world. Until next time, keep questioning, keep learning, and keep revolutionizing the digital world!

And with that, I appreciate your continued support and engagement with The Digital Revolution podcast. Stay tuned for more insightful episodes where we talk about the latest trends and innovations in intelligent technologies. Until next time, keep exploring the frontiers of intelligent technology!

Don't forget to follow this podcast series to stay up-to-date on the ever-changing world of digital transformation.

Thank you for supporting the revolution.

The Digital Revolution with Jim Kunkle - 2025