IoT supply chains introduce multiple parties that can handle embedded credentials, provisioning systems, and remote support functions. Those elements behave like NHIs because they authenticate systems and often persist long after the commercial relationship changes, which increases the chance of stale access and hidden privilege.
Why This Matters for Security Teams
IoT supply chains expand identity risk because every manufacturer, integrator, firmware vendor, logistics partner, and remote support provider may touch the same device trust chain. Each touchpoint can introduce credentials, certificates, API keys, or service accounts that behave like NHIs, especially when they are embedded early and forgotten later. That creates a long tail of access that survives contracts, product refreshes, and even ownership changes. Current guidance from the OWASP Non-Human Identity Top 10 and NIST’s broader identity governance thinking both point to the same problem: static trust does not fit distributed, machine-to-machine ecosystems. NHIMG research shows the exposure is not theoretical, with Ultimate Guide to NHIs reporting that 92% of organisations expose NHIs to third parties and 97% of NHIs carry excessive privileges. In practice, many security teams discover these identities only after a supplier relationship ends or a compromised device is already being used as a foothold.
How It Works in Practice
The risk usually starts at provisioning. Device makers often ship with factory certificates, bootstrap tokens, or shared secrets that are meant to be replaced but are not always rotated correctly. During deployment, channel partners may create service accounts for telemetry, remote diagnostics, OTA updates, or warehouse automation. Those accounts can persist across environments and remain valid long after the original use case is gone. The result is a supply chain full of machine identities with unclear ownership, weak lifecycle controls, and excessive privilege.
Security teams need to treat these identities as first-class assets, not incidental configuration. Practical controls include:
- Inventory every device identity, certificate, token, and remote support account across suppliers and resellers.
- Replace shared or long-lived secrets with short-lived credentials and explicit expiration.
- Bind device trust to workload identity where possible, using cryptographic proof rather than static password-style access.
- Require revocation and offboarding clauses in supplier contracts so identities are removed when a relationship ends.
- Monitor for dormant credentials, vendor-admin accounts, and unexpected network paths between devices and support systems.
The 52 NHI Breaches Analysis and the NIST Cybersecurity Framework 2.0 both reinforce the same operational lesson: visibility, access control, and lifecycle management must extend beyond the enterprise boundary. These controls tend to break down in multi-tier manufacturing environments because downstream integrators and repair partners often inherit credentials without a reliable revocation process.
Common Variations and Edge Cases
Tighter supplier control often increases operational overhead, requiring organisations to balance device availability against revocation discipline. That tradeoff is especially visible in medical, industrial, and consumer IoT environments where uptime, warranty support, and field servicing can conflict with strict identity hygiene.
There is no universal standard for this yet, but current guidance suggests a few patterns. First, OEM-managed remote access should be time-bound and event-driven rather than permanently enabled. Second, certificate-based trust is stronger than shared passwords, but certificates still become risky when renewal and revocation are unmanaged. Third, legacy fleets may not support modern workload identity, so compensating controls such as segmented networks, proxy-based access, and strict monitoring become necessary. Finally, third-party access reviews must include suppliers, repair contractors, and cloud operators, not only internal administrators.
NHIMG’s Top 10 NHI Issues is useful here because it frames the problem as lifecycle failure, not just credential sprawl. In short, IoT supply chains create NHI risk when identity ownership is fragmented and no one is accountable for removing access at the end of the device or vendor lifecycle.
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 and CSA MAESTRO address the attack and risk surface, while NIST AI RMF and NIST CSF 2.0 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-01 | Covers discovery and inventory gaps for machine identities in supplier ecosystems. |
| CSA MAESTRO | Supplier-managed IoT devices are autonomous workloads that need lifecycle governance. | |
| NIST AI RMF | GOVERN | Governance is needed for accountable ownership of machine identities across vendors. |
| NIST CSF 2.0 | PR.AC-1 | Identity and credential issuance across third parties maps to access control governance. |
Build a complete inventory of device secrets, certificates, and service accounts across all suppliers.
