Industrial control room with operators monitoring SCADA systems on large screens, showcasing the critical OT environment where vulnerability management ensures operational continuity.

Vulnerability Management in OT: Beyond CVSS Scores to Operational Resilience

In Operational Technology (OT) environments, where systems such as SCADA, PLCs, DCS, and safety instrumentation control critical infrastructure, vulnerability is not just deploying the network scanning tool to know the CVE, CWE and CVSS score but to fix the vulnerabilities in an organized manner. Effective vulnerability management in OT is about identification, assessment, prioritization, and remediation.

In our recent OT Cybersecurity webinar series, Mubarik Mustafa, Principal Consultant for OT/ICS cybersecurity at ACET Solutions, shared valuable perspectives on vulnerability management in OT, highlighting the importance of establishing strong and structured vulnerability management processes to enhance overall cybersecurity effectiveness.

Mubarik Mustafa said, “OT vulnerabilities are the silent killers of critical infrastructure. You might not see them—until they shut down your plant.”

To watch the webinar recording click here.

In this article, we will cover the vulnerability types in OT with examples and practical ways to fix them, and the vulnerability management processes.

Understanding the Vulnerability Management in OT Environment

“True vulnerability management is very tedious and time-consuming. It’s not about just deploying a solution that scans the network and tells you the CVSS score.” Mubarik

OT systems form the foundation of critical sectors like power generation, water treatment, oil and gas, and industrial manufacturing. Even a single vulnerability can disrupt operations, pose safety risks, or result in severe consequences.

It is a necessary first step to uncover vulnerabilities using CVE IDs, CWE types, and CVSS scores but it’s far from sufficient. The real challenge lies in what comes next: remediating those vulnerabilities in a methodical and prioritized manner, without disrupting the fragile stability of OT environments.

Mubarik Mustafa added, “In OT environment, availability is the king. You cannot shut down any PLC just because you have to upgrade the firmware.”

Unlike IT networks, where patching can often be done quickly and remotely, OT systems require careful planning, coordination, and sometimes even physical intervention to address risks safely.

5 Types of Vulnerabilities in OT

Vulnerability is a weakness or flaw in a computer system, network system or associated process that can be exploited to compromise safety, availability, integrity, or confidentiality.  Some of the major type of vulnerability are:

  1. Product or technology vulnerabilities in OT stem from outdated hardware or software, such as legacy PLCs, industrial computers running unsupported operating systems, or unpatched firmware and insecure communication protocols lacking encryption or authentication increase the risk.
  2. Implementation Gaps: Many vulnerabilities are often overlooked during ICS and cybersecurity implementation, such as the use of weak or default passwords and improperly configured firewalls.
  3. Physical vulnerabilities in OT are unlocked cabinet doors or unrestricted physical access to control rooms, servers, and operator workstations.
  4. Process vulnerabilities in OT often arise from the absence of defined procedures, such as managing USB access or controlling user privileges. Without clear policies, unauthorized devices or users can gain access to critical systems.
  5. People-related vulnerabilities are a biggest concern in OT. Issues such as lack of cybersecurity training, poor awareness of security practices, and habits like password sharing can significantly weaken overall defenses.

 

Mubarik Mustafa said, “Vulnerabilities aren’t introduced into products or technologies—they already exist and are simply discovered over time.”

How do we address these vulnerabilities?

Addressing vulnerabilities in OT isn’t as straightforward as it is in IT. While best practices suggest installing patches and upgrading firmware as soon as updates are released, this approach often isn’t feasible in OT.

A Vulnerability Management Solution in OT security only help in identify the known issues such as CVE IDs, CWE types, and CVSS scores across devices and systems. However, this is only the first step. The true challenge lies in how organizations respond by prioritizing, planning, and safely remediating these vulnerabilities within the constraints of OT environment. In OT environments, identifying a critical asset with a known vulnerability is just the beginning. Often, these assets can’t simply be shut down for immediate patching or fixes—doing so could disrupt essential operations.

How to manage vulnerabilities?

Managing vulnerabilities in OT requires a structured, risk-aware approach that balances security with operational continuity.

  • Identification: Identifying vulnerabilities in an organized and effective manner is crucial for securing OT environments. Best practice involves considering multiple parameters—starting with the type of vulnerability and whether it applies to your specific asset. To do this accurately, you must have clear visibility into your asset’s make, model, and firmware version. This helps determine if a known vulnerability can truly impact that asset.
  • Assessment: Assessing vulnerabilities in OT isn’t just about detection, it’s about making informed decisions. Start by reviewing the CVSS score to understand severity, then consult security bulletins and vendor advisories related to the CVE. Consider the exploitation impact in your specific environment to determine if remediation is necessary, and if so, when it should be scheduled.

 

Mubarik Mustaf said, “Not all vulnerabilities are equal. Focus on the 2% that could halt production—ignore the noise.”

 

  • Prioritization: Prioritization is a key step in effective vulnerability management, especially in OT environments where uptime is critical. Not every vulnerability poses the same level of threat, so it’s important to assess based on factors like CVSS scores, the criticality of the affected asset, and the potential impact of exploitation. A vulnerability on a core control system is far more urgent than one on a non-critical device.
  • Remediation: It’s a critical step that turns vulnerability insights into real security improvements. It must be carefully planned to avoid disrupting operations.

 

“Don’t sit and wait for unpatchable or non-upgradable assets—implement alternative countermeasures instead,” said Mubarik.

Vulnerability Management Process:

Vulnerability management process is a structured approach used to identify, assess, prioritize, and remediate security vulnerabilities in systems, applications, and devices.

Step by step process of Vulnerability Management Process:

  • Maintain an accurate asset inventory of all OT assets with at least the following information (including network assets):
    • Make/Model
    • Current firmware
    • Location (physical/logical)
    • Criticality
    • Ownership
    • Redundancy
  • Maintain an accurate inventory of all operating systems, software, versions, and installed patches on all computers.
  • Keep a track of security advisories released by the ICS vendors (including CWE, CVE, CVSS, affected products, affected versions/firmware, remediations)
  • Compare the lists of affected products/versions/firmware in the advisories with asset/software inventory to determine which products are affected in your organization for each CWE.
  • Determine which vulnerabilities are applicable to which assets
  • Determine which vulnerabilities need to be addressed immediately
  • Determine the remediations available for each vulnerability (not all are patchable)
  • Determine which assets can be patched/upgraded without impacting operations
  • Determine alternate countermeasures for un-patchable assets
  • Follow the change management process within your organization to implement the countermeasures

Conclusion

True vulnerability management goes far beyond simply running a scanning tool to collect CVEs, CWEs, and CVSS scores. It’s a complex, time-consuming process that demands specialized expertise to determine what vulnerabilities need to be addressed, when and where to fix them, and why certain actions are necessary—all in a structured, risk-based manner. To do this effectively, organizations should either build a dedicated internal team or partner with external experts who understand the unique challenges of securing OT environments.

To learn more about how ACET Solutions can help you with Vulnerability Management visit our website.

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