Why do service accounts and shared admin identities complicate Zero Standing Privilege?

Why This Matters for Security Teams

zero standing privilege depends on privilege being absent until it is explicitly needed, then removed as soon as the task ends. Service accounts and shared admin identities weaken that model because they blur who is acting, when access is justified, and whether the privilege was actually required. That makes review, containment, and incident scoping much harder, especially when the same identity is reused across jobs, scripts, and operators.

NHI Management Group research shows that only 5.7% of organisations have full visibility into their service accounts, while 71% of NHIs are not rotated within recommended time frames. That visibility gap is why shared identities so often become the quiet exception that bypasses ZSP discipline. The issue is not only over-permissioning, but also that standing access remains available to anyone who knows the credential or inherits the process. Guidance from the OWASP Non-Human Identity Top 10 and the Ultimate Guide to NHIs both point to the same operational problem: privileged identities that persist outside a narrow task window defeat the intent of standing-privilege reduction.

In practice, many security teams encounter the real risk only after a shared admin account has already been used by multiple operators, making attribution and containment slower than the original access event.

How It Works in Practice

ZSP works best when each privileged action is tied to a unique identity, a specific approval, and a short-lived credential. For human admins, that usually means just-in-time elevation with per-session authorization. For service accounts, it means replacing shared accounts with workload identity, scoped tokens, and automation that can prove what the workload is trying to do at runtime.

A practical design usually includes:

• Unique operator identities for humans, with strong authentication and session logging.
• Ephemeral credentials issued only for the approved task, then revoked automatically.
• Workload identity for non-human actors, so the system can distinguish one service from another.
• Policy evaluation at request time, not just during provisioning, so context can affect access decisions.
• Separate secrets for separate jobs, with no reuse across teams, tools, or environments.

This is where current guidance from the NIST Cybersecurity Framework 2.0 and the Ultimate Guide to NHIs aligns with operational reality: access must be measurable, revocable, and bound to lifecycle controls. Shared admin identities undermine that because they compress multiple actors into one authorization trail. Even if a vault rotates the password, the access path still exists, and the same standing credential may be used in scripts, emergency workarounds, or cross-team handoffs. Current best practice is evolving toward workload-aware controls, but there is no universal standard for every environment yet.

These controls tend to break down in legacy estates with batch jobs, embedded credentials, and vendor-managed service accounts because the application flow was never designed around unique, short-lived identity.

Common Variations and Edge Cases

Tighter privilege controls often increase operational overhead, requiring organisations to balance reduced exposure against automation reliability and response speed. That tradeoff is most visible in break-glass scenarios, third-party integrations, and systems that cannot easily support per-task identity. In those cases, teams sometimes retain shared credentials temporarily, but that should be treated as an exception with compensating monitoring rather than a normal operating model.

There is also a distinction between a shared admin identity and a shared function. A shared function can often be refactored into role-based approval plus unique sessions, while a shared identity keeps the accountability problem intact. For long-running services, static credentials are especially problematic because the privilege window stretches far beyond the actual work being performed. Best practice is to move toward short TTL tokens, scoped permissions, and strong logging that preserves attribution even when automation is doing the work.

NHIMG’s Top 10 NHI Issues highlights why this matters across environments: excessive privilege and weak lifecycle control are recurring patterns, not edge cases. In regulated or highly automated environments, the question is not whether shared identities are convenient, but whether the convenience is worth the loss of containment when an incident occurs.

Related resources from NHI Mgmt Group

• When should organisations prioritise Zero Standing Privilege for non-human identities?
• Why do Active Directory service accounts complicate zero trust programs?
• Why do non-human identities complicate zero trust architecture?
• Why do NHIs complicate zero trust and least privilege efforts?