OT Vulnerability Management: A Beginners Guide to Network Defense, Change Management, and System Hardening

July 21, 2023

Let’s dive into OT vulnerability management. Given the recent surge in ransomware attacks, especially those targeting obsolete Windows operating systems, it’s time rethink mitigation strategies. Fighting cybersecurity battles isn’t about patching vulnerabilities as they arise, but more about seeing the wider scope – understanding the probability and consequences, making smart decisions, and prioritizing.


Ticking Time Bombs in Your OT Environment 

Network hosts that seem dormant or invisible could be the ticking time bombs in your OT environment. The same goes for the active ports, services, and server applications that could expose system vulnerabilities. Remember, our OT vulnerability scanners are only as reliable as their last update – regular, pre-use updates are a must for accurate and timely detection.

It can be resource-consuming, but it’s undeniably a critical element of your security fortress. Patch those vulnerabilities before they’re found and exploited!

Now, let’s talk about two non-negotiables: network segregation and system hardening. These aren’t merely buzzwords. They are powerful tactics to fortify your OT space and reduce the risk of wide-scale compromises.


OT Vulnerability Management – Change Management Policy

Moving on, an integral aspect of OT vulnerability management is change management. We live in a world of constant evolution – whether it be network architecture, organizational processes, or threat landscape. Sticking to yesterday’s cybersecurity plan is like fighting tomorrow’s war with yesterday’s weapons. Regular, systematic review and updates are not an option – they are a necessity. In OT, a comprehensive change management policy is paramount. The policy should address the when, why, and how of changes – be it system ownership, architecture, interconnections, or scope. Think of it as the traffic light on your cyber highway – controlling, documenting, and prioritizing changes.

Creating a security baseline – a set reference point against your organizational risk tolerance – is crucial. This helps gauge changes, evaluate their impact, and monitor variances. Remember, in an OT network, availability usually trumps confidentiality, so plan your responses accordingly. Unapproved changes demand immediate investigation. You wouldn’t want to trigger an unintentional cascade of disruptions in your ICS environment due to an abrupt, automated reversion.

Change management policy must prioritize robust documentation and tracking. The rule is simple – significant changes deserve significant documentation. Archive libraries, hardware inventories, network architecture schematics, and equipment change history are all integral pieces of the puzzle.

Configuration change management and configuration auditing go hand-in-hand here. One manages the changes, while the other validates and ensures compliance with best practices.

Never forget – in the game of cybersecurity, prevention is always better than cure.

DeepSeas MDR+ for OT, IT, mobile and cloud is a comprehensive Managed Detection & Response solution designed to protect businesses from sophisticated cyber threats. Moreover, DeepSeas MDR+ is well suited for managing the unique risks of OT systems. Our cybersecurity experts have decades of experience in driving complex managed cybersecurity program across multiple industries.

This beginner’s guide to OT vulnerability management was written by a valued member of our DeepSeas crew,