What should organisations do first with service accounts and vendor access?

Start by inventorying every service account, automation, and third-party access path that can reach sensitive systems, then remove broad permissions and rotate the associated secrets. Those identities often bypass human controls, so they need ownership, scope, and offboarding discipline from the start.

Why the first move is inventory, not cleanup

The right first step is to find every non-human access path before you try to tighten it. Service accounts, automation jobs, integrations, and vendor connections often sit outside the normal joiner, mover, leaver process, so they are easy to miss and hard to govern unless they are explicitly enumerated and owned.

That inventory should be more than a list of names. It needs to show what each identity can reach, where its secrets live, which business process depends on it, and whether it is still needed. Without that baseline, permission reduction and secret rotation become partial fixes that leave hidden access behind.

For a useful starting inventory, organisations should distinguish between identities that authenticate directly, credentials that enable access, and third-party paths that inherit trust through federation, API keys, tokens, or shared accounts. Those are different control problems even if they all look like “service access” in an audit spreadsheet.

How scope and privilege get out of control

Once the inventory exists, the next question is whether each identity has a narrowly defined purpose. Broad permissions are common because service accounts are often created to make delivery fast, then left untouched while applications, vendors, and environments change around them. Over time, that turns a convenience account into a standing access path.

vendor access deserves the same scrutiny because external support, contractors, and suppliers frequently accumulate exceptions, especially when they need production or emergency access. NHIMG’s Third-Party, B2B and Contractor Access Guide is a useful reference point for the controls that matter here: sponsorship, time limits, reviews, and least privilege.

If an identity can reach sensitive systems, it should have one clear owner, one documented purpose, and the smallest workable set of permissions. If those three things are missing, the account is already operating with excess trust, even if no misuse has been observed.

Why offboarding and rotation must happen early

The first cleanup action after inventory is usually to remove broad permissions and rotate the secrets tied to high-value access. That order matters because broad entitlements and long-lived credentials are the main reasons service accounts and vendor paths become durable compromise points rather than short-lived operational tools.

Rotation is especially important when the secret is shared, embedded, or difficult to trace back to a single application owner. NHIMG’s Guide to NHI Rotation Challenges is relevant because it frames rotation as a lifecycle problem, not just a password change. If you cannot reliably rotate without breaking production, the real issue is dependency mapping and ownership, not the rotation command itself.

Offboarding should be treated the same way. If a vendor contract ends, an integration is retired, or automation is replaced, the access path should be removed, not merely ignored. NHIMG’s Ultimate Guide to NHIs is a practical parent resource for this lifecycle view, especially where service accounts, workload identities, and secrets are involved.

Risk and Threat Considerations

Service accounts and vendor access are high-value targets because they often bypass human review, MFA workflows, and normal user offboarding. When they are overprivileged or left unrotated, an attacker can move from a single credential theft to broad access, persistence, or lateral movement with very little additional effort.

Failure mechanism: Broad entitlements, shared secrets, stale vendor access, and missing ownership create a durable path that is difficult to detect and even harder to revoke quickly once compromise occurs.

Impact: A single exposed secret or abused third-party path can expose sensitive systems, enable unauthorized data access, and extend compromise beyond the original account or integration.

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 surface, NIST SP 800-53 Rev 5, CIS Controls v8 and CSA Cloud Controls Matrix set the technical controls, and ISO/IEC 27001:2022 defines the regulatory obligations.

Framework	Control / Reference	Relevance
OWASP Non-Human Identity Top 10	NHI-01 — Improper Offboarding	Vendor and service-account access must be removed when the business need ends.
	NHI-02 — Secret Leakage	The question centers on secret rotation for access paths that can reach sensitive systems.
	NHI-05 — Overprivileged NHI	Removing broad permissions is the core control for service accounts and vendor access.
Recommendation — Revoke retired service and vendor identities promptly and verify all dependent secrets are disabled. Rotate exposed secrets and move sensitive access to controlled secret-management processes. Trim each non-human identity to the minimum permissions needed for its documented purpose.
NIST SP 800-53 Rev 5	AC-2 — Account Management	Inventory, ownership, and offboarding are account-management duties for service and vendor access.
	AC-6 — Least Privilege	The question explicitly calls for removing broad permissions from sensitive access paths.
	IA-5 — Authenticator Management	Secret rotation is a direct authenticator-management requirement for non-human access paths.
Recommendation — Maintain a current inventory of accounts and remove access when it is no longer required. Limit each service account and vendor account to the minimum privileges needed. Rotate and retire authenticators on a defined schedule and after role or vendor changes.
CIS Controls v8	CIS-5 — Account Management	This topic begins with identifying accounts and third-party access paths, then removing excess access.
	CIS-6 — Access Control Management	Removing broad permissions and constraining vendor access is an access-control task.
Recommendation — Inventory all accounts and disable or remove any that are no longer needed. Enforce least privilege and regularly review who can reach sensitive systems.
CSA Cloud Controls Matrix	IAM — Identity and Access Management	Cloud and vendor access paths depend on identity inventory, privilege reduction, and offboarding.
Recommendation — Map every service and third-party identity to an owner, purpose, and revocation process.
ISO/IEC 27001:2022	A.5.15 — Access control	The subject is fundamentally about limiting and reviewing access to sensitive systems.
Recommendation — Define and enforce access rules that keep non-human access constrained and reviewable.

Practitioner Guidance

What to prioritise: Start with identities that can reach production, administrative consoles, data stores, or CI/CD systems. Those are the access paths where overprivilege and stale secrets create the most immediate blast radius.

What to verify: Confirm each account has a named owner, a documented business purpose, and a revocation path that works without waiting for an incident. If you cannot answer who owns it, why it exists, and how it is retired, it is not yet governable.

Common mistake: Teams often rotate a secret but leave the permissions and third-party trust unchanged. That reduces one risk while preserving the larger one, which is the standing authority attached to the identity.

Practitioner takeaway: Inventory first, then reduce privilege and rotate secrets, because governance only becomes effective once you know which non-human access paths still exist and who is accountable for each one.