In many manufacturing plants, the most dangerous access is also the most normalised one: remote access granted to suppliers for support and maintenance.
PLCs. SCADA. Production lines. But also elevators, access control, HVAC, energy management systems.
These connections exist for good reasons: availability, speed, operational continuity. Yet too often, they rely on outdated assumptions of trust.
Shared credentials. Permanent VPNs. 4G modems installed “temporarily” and never removed. Remote desktop sessions with no monitoring, no logging, no expiry.
This is not operational efficiency. It is unmanaged exposure.
Attackers rarely start with hardened corporate IT. They enter where governance is weakest and visibility is lowest: supplier access, technical systems, OT environments assumed to be isolated but quietly connected.
Once inside, the impact is not theoretical:
Production stops.
Safety margins erode.
Recovery costs explode.
And under NIS 2, accountability no longer stops at IT.
The real issue is not remote support. It is blind trust without control.
Every manufacturing executive should be able to answer three questions without hesitation:
Who can access our systems?
Under which conditions?
How fast can we cut that access if something goes wrong?
If the answer is unclear, the risk is already accepted by default.
Remote access must become a controlled, auditable gate
Supplier remote access is often the fastest way to fix a problem, and the fastest way for an attacker to enter a plant. The goal is not to block suppliers. It is to turn remote access into a controlled, auditable gate:
Use a dedicated OT remote access gateway that routes every supplier connection through a controlled entry point, not a generic VPN into plant networks.
Keep suppliers away from the shop floor layer by design. Enforce clear separation between business IT, OT supervision, and the devices that run production and technical systems.
Make access exceptional, not permanent. Require MFA, time-limited access, and permissions restricted to the exact system and task.
Ensure full traceability. Log, and ideally record, supplier sessions. No direct remote access exposed to the internet.
Treat it as a high-risk governance topic. Integrate it with privileged access management, embed requirements in contracts, and review supplier access rights regularly under your ISMS and NIS2 approach.
Bottom line
If you cannot answer “who accessed what, when, and why” in two minutes, your remote access model is not support. It is exposure.
If you need support to design the right solution, not only the technical controls but also the people and governance model, contact us at DigiSôter.