- Critical OT & Industry 4.0
- Microsoft WSUS
Case Study: Secure Offline Patching for Air-Gapped OT Networks
Gas Distribution Operator in Europe
Preventing file corruption during large patch package transfers
Limited bandwidth preventing full system backup transfers
Meeting strict regulatory requirements including NIS2 and French LPM frameworks
Need / Problem / Context
Automating Secure Patching for Air-Gapped OT Infrastructure
A regional gas distribution operator in Europe needed to ensure regular operating system and application updates across a critical OT network controlling gas distribution infrastructure.
For cybersecurity reasons, the OT environment was fully air-gapped and disconnected from the Internet. While this architecture protected operational systems from remote cyber threats, it also made patch management — including WSUS (Windows Server Update Services) synchronization — extremely complex. Updates had to be transferred manually between IT and OT environments, creating operational overhead and increasing the risk of human error or data corruption.
The organization therefore needed a secure and automated mechanism to transfer validated update packages — including WSUS update flows — from the IT environment to the isolated OT network, while preserving strict one-way security separation and maintaining compliance with European critical infrastructure cybersecurity regulations (under NIS2).
Solution Deployed
A Cyberium unidirectional gateway architecture was deployed to securely transfer validated update packages from the IT patch management infrastructure to the isolated OT network while preserving strict air-gap protection. The architecture enables automated patch distribution to OT systems without introducing any inbound connectivity risk to operational infrastructure.
4x OWA 3U pack @ 1 Gbps
Four unidirectional security gateways were deployed to securely transfer update packages from the IT environment to the air-gapped OT network while enforcing strict one-way communication.
SFTP Connector
Update packages and patch repositories are transferred through secure file transfer mechanisms, ensuring reliable delivery of validated update content
Windows WSUS
A dedicated synchronization component enables automated replication of Microsoft update repositories between IT and OT environments while preserving the integrity of patch metadata and packages
Outcomes & Benefits
The deployment enabled the operator to automate patch management for its air-gapped OT infrastructure while maintaining strict cybersecurity protections and regulatory compliance
Achieved full compliance with EU NIS2 and French LPM cybersecurity regulation
Replaced a manual and resource-intensive update process and an unreliable third-party solution
Fully automated the OT patching workflow with no operational overhead
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