They create audit risk when their permissions are broader than the workflow they support or when no one can explain why the identity still exists. Auditors look for ownership, access scope, rotation, and deprovisioning evidence. Without those controls, machine identities become unmanaged exceptions inside the ISMS.
Why This Matters for Security Teams
service account and api key are audit risks because they often outlive the business process that created them. When an identity is tied to a workflow rather than a person, teams can lose track of ownership, purpose, and expiry. That is exactly where iso 27001 evidence starts to matter: auditors want to see who approved it, what it can touch, how it is rotated, and how it is removed when no longer needed. The problem is not the identity type itself, but the lack of control around it.
Machine identities also tend to hide inside CI/CD, integration jobs, and SaaS connectors, which makes them easy to miss during access reviews. NHIMG research shows that secrets exposure is not theoretical: The State of Secrets Sprawl 2026 found 28.65 million new hardcoded secrets in public GitHub commits in 2025 alone. For governance teams, that volume turns “temporary” access into a persistent exposure problem. Current guidance suggests treating these identities as first-class assets under the ISMS, not as backend implementation detail. In practice, many security teams encounter audit findings only after an expired key is still active or a critical integration cannot be explained during evidence collection.
How It Works in Practice
The cleanest way to reduce ISO 27001 audit risk is to make every service account or API key answer four questions: who owns it, what business function it supports, what it can access, and when it is removed. That means pairing RBAC with explicit asset ownership, documented justification, rotation evidence, and deprovisioning triggers. Where the workflow is predictable, JIT credential provisioning is stronger than static secrets because access exists only for the task window and is revoked automatically afterward. For machine identities, that often means using workload identity rather than long-lived shared credentials, so the system proves what it is at request time instead of relying on a reusable secret.
ISO 27001 auditors usually do not ask for perfection; they ask for traceability. If a service account is used by a nightly billing job, the evidence should show the job owner, the entitlement scope, the last rotation date, and the retirement path if the job is replaced. NIST’s NIST Cybersecurity Framework 2.0 aligns well here because it pushes organisations toward asset visibility, access governance, and continuous risk management. For identity sprawl, Guide to the Secret Sprawl Challenge is a useful reminder that detection alone is not enough if revocation and ownership are missing.
- Assign a named business and technical owner to every machine identity.
- Replace shared API keys with short-lived, task-scoped credentials where possible.
- Document the minimum access scope and review it on a fixed cadence.
- Record rotation, revocation, and decommissioning evidence in the ISMS.
These controls tend to break down in legacy automation platforms and vendor integrations that cannot issue short-lived tokens because static secrets are still the only supported authentication method.
Common Variations and Edge Cases
Tighter secret controls often increase operational overhead, requiring organisations to balance auditability against integration friction. That tradeoff is especially visible in legacy ERP jobs, third-party SaaS connectors, and cross-account cloud pipelines, where replacing a stable API key can take more coordination than the original integration ever did. Best practice is evolving here: there is no universal standard for every environment, but current guidance still favours shortening secret lifetime and reducing blast radius wherever technical constraints allow.
The biggest exception is when a machine identity is not really “service-only” at all. Some API keys are embedded in customer-facing apps, some service accounts are shared across environments, and some automation credentials are reused by multiple teams. Those patterns make audit evidence weaker because the identity no longer maps cleanly to one purpose. NHIMG breach analysis shows why that matters operationally: the Dropbox Sign breach illustrates how exposed credentials can quickly become a governance and incident response problem, not just a secrets management issue. For broader context on non-human identity exposure, see the Ultimate Guide to NHIs — What are Non-Human Identities. In environments with heavy third-party dependencies, shared admin keys, or no central secret inventory, audit readiness degrades fastest because ownership evidence becomes fragmented across teams and systems.
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 address the attack and risk surface, while NIST CSF 2.0 and NIST AI RMF set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-03 | Addresses rotation and lifecycle control for non-human credentials. |
| NIST CSF 2.0 | PR.AC-4 | Maps to access control and least privilege for machine identities. |
| NIST AI RMF | Supports governance and accountability for automated, identity-using workflows. |
Inventory every service account and API key, then rotate or retire anything without a defined owner and expiry.
Related resources from NHI Mgmt Group
- Why do service accounts and API keys create so much supply chain risk?
- Why do non-human identities create more audit risk than human accounts?
- What problem does ownership attribution solve for service accounts and API keys?
- Why do service accounts and API keys create more risk than many human accounts?
