Manufacturing teams should start by mapping every external access path, then limit each vendor to the minimum ports, systems, and sessions needed for the task. Fine-grained controls such as PAM and Zero Trust Network Access reduce broad exposure while preserving necessary support. The key is to treat vendor access as a controlled exception, not a permanent extension of the internal network.
How to reduce third-party risk without turning vendor access into a bottleneck
The practical balance is to shrink each vendor’s blast radius, not to remove vendor access altogether. That means mapping every path a third party can use, then narrowing it to only the systems, ports, and sessions needed for the task. The more precise the boundary, the less operational drag you create while still cutting exposure.
Broad, always-on vendor access is usually the real source of slowdown later, because teams spend time approving exceptions, investigating noise, and cleaning up after overexposed connections. A narrower access model can actually speed support if it is predictable, time-bound, and easy to request.
What “minimum necessary access” looks like in manufacturing environments
Manufacturing teams usually have a mix of plant-floor systems, remote support tooling, and supplier-managed software. The right question is not whether vendors can access production, but which exact assets, from which source, for which duration, and under what approval path. That is where controls like OWASP Non-Human Identity Top 10 and CSA Cloud Controls Matrix become useful as control lenses for access minimisation and third-party governance.
In practice, minimum necessary access means segmenting vendor connections by function, not by convenience. If a supplier only needs one machine, one maintenance window, or one API path, do not inherit the rest of the environment as a side effect. The same principle applies whether the access is via remote desktop, a jump host, an integration account, or a support token.
Time-bounding access matters as much as scope. For vendors, a short-lived session with a clear expiry is usually safer than a standing account that must be remembered and manually reviewed. If the task recurs, treat that as a justified workflow to formalise rather than leaving it as a permanent exception.
How to keep vendor work moving while tightening control
The main operational trick is to separate access design from support responsiveness. Vendors do not need broad trust if your request process is fast, approval criteria are clear, and temporary access is easy to issue and revoke. NIST Cybersecurity Framework 2.0 is useful here because it supports governance, asset visibility, and access control as part of a steady operating model rather than a one-off lockdown.
Manufacturing teams should also distinguish between vendor identity and vendor activity. A vendor may be legitimate, but a specific session, credential, or integration path can still be too powerful for the work being done. That is why PAM and Zero Trust Network Access work best when they enforce the task itself, not just the fact that the requester is approved.
If a vendor truly needs broader access to complete a high-value task, make that an exception with a defined owner, start and end time, and post-use review. This avoids the common failure mode where temporary operational need quietly becomes permanent privilege.
Where third-party risk usually hides in plant and supplier workflows
The biggest hidden risk is usually inherited access, where one vendor relationship opens the door to multiple systems through shared credentials, reused accounts, or loosely governed remote tools. That pattern shows up frequently in third-party incidents, including supply-chain compromise and credential abuse cases captured in Ultimate Guide to NHIs, Key Challenges and Risks and The 52 NHI Breaches Report.
Manufacturing environments are especially sensitive because support paths often bridge IT and OT. A vendor tool that looks harmless on the IT side can still become a high-impact path into production operations if it can reach controllers, historians, recipes, or maintenance systems. That is why access scope should be tied to the smallest controllable business function, not to the vendor relationship as a whole.
Another common weak point is persistence after the work is finished. If access is not removed, rotated, or re-approved after the task ends, the environment accrues silent exposure. That creates both security risk and audit friction, because the organisation can no longer explain why the access still exists.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 addresses the attack and risk surface, while NIST CSF 2.0, NIST Zero Trust (SP 800-207) and NIST SP 800-53 Rev 5 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-05 — Overprivileged NHI | Vendor access often becomes overprivileged and expands blast radius. |
| NHI-08 — Environment Isolation | Manufacturing vendor paths should stay segmented from broader production access. | |
| NHI-07 — Long-Lived Secrets | Standing vendor credentials prolong exposure and slow offboarding. | |
| Recommendation — Limit each vendor account to the minimum ports, systems, and sessions needed. Isolate vendor access paths so support work cannot wander across environments. Use short-lived access and rotate any vendor secrets that must persist. | ||
| NIST CSF 2.0 | PR.AA-05 — Identities Are Managed and Access Is Authorized | The question is about authorising third-party access without excessive exposure. |
| GV.SC-04 — Third-Party Risk Management | Third-party risk is central to vendor access decisions and oversight. | |
| Recommendation — Authorize only the specific vendor access needed for the task. Define and govern supplier access expectations, review points, and exceptions. | ||
| NIST Zero Trust (SP 800-207) | AC-4 — Information Flow Enforcement | Zero Trust access should restrict vendor movement to approved flows. |
| Recommendation — Enforce narrow access paths for vendors instead of broad network trust. | ||
| NIST SP 800-53 Rev 5 | AC-6 — Least Privilege | Minimum necessary vendor access is the core control objective. |
| IA-5 — Authenticator Management | Vendor support access depends on controlling credentials and their lifecycle. | |
| Recommendation — Grant vendors only the privileges required to complete each approved task. Issue, expire, and revoke vendor authenticators on a strict lifecycle. | ||
Practitioner Guidance
What to prioritise: Start with your highest-risk vendor paths, especially remote support routes that can reach production or shared admin planes. Those are the places where a small access change gives the biggest reduction in exposure.
What to verify: Confirm that each vendor account, token, or session is tied to one named purpose, one owner, and one expiry condition. If you cannot explain why the access must still exist, it is already too broad.
Decision rule: If a vendor request requires standing access, treat that as a design failure unless the business case is explicit, reviewed, and periodically re-justified. If the work can be done with a short-lived session or just-in-time access, use that instead.
Practitioner takeaway: The best third-party control in manufacturing is the one that feels lightweight to the vendor because it is precise for the defender, not because it is broad and tolerated.
Related resources from NHI Mgmt Group
- How should security teams build an IT vendor management policy that reduces third-party risk without slowing operations?
- How should organisations audit third-party remote access to reduce vendor risk without slowing support operations?
- How can organisations reduce third-party identity risk without slowing operations?
- How should security teams structure third-party security testing programmes to reduce risk without slowing down business relationships?
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on September 26, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
