They should govern service principals as first-class identities with ownership, expiry, recertification, and credential rotation. When these non-human identities drift unmanaged, a human compromise can pivot into application-level access that bypasses normal workforce controls and survives well beyond the initial incident.
Why service principals need the same ownership discipline as users
When service principals can reach production systems, they are not “just technical plumbing.” They represent delegated authority that can outlive staff changes, application refactors, and even the original deployment team, so IAM teams need the same governance mindset they already apply to workforce identities.
That means assigning a clear owner, defining the business purpose, and treating each service principal as a governed access path with a lifecycle, not a static configuration item. If the identity can authenticate, call APIs, or read secrets, it deserves explicit accountability and periodic review.
What changes operationally when service principals share the attack surface
The practical shift is that compromise paths stop at neither a human account nor a non-human account boundary. A phished user, stolen session, or overprivileged admin can often reach app credentials, consent grants, certificates, or token material that unlock service principal access long after the original incident is contained.
That is why teams should inventory service principals alongside user accounts, compare privilege to actual workload need, and remove stale or duplicated principals before they become durable backdoors. The important question is not whether the principal is human, but whether it can still move the attacker into sensitive systems.
Key management matters here as well, because long-lived secrets and certificates are often the mechanism that keeps the access path alive. The tighter the secret lifecycle, the less opportunity an attacker has to reuse a harvested credential or pivot from one identity class into another.
How IAM teams should govern service principals as first-class identities
Governance needs a full control set: ownership, expiration, recertification, least privilege, and credential rotation. The same review logic used for users should be adapted for service principals, with extra attention to non-interactive access, app registrations, and any delegated permissions that can expand blast radius.
Where a principal no longer has a clear business owner or documented workload, it should be treated as an orphaned identity and retired or revalidated. Where a principal still matters, its permissions, secrets, and trust relationships should be reviewed on a fixed cadence, especially after deployment changes, vendor transitions, or incident response.
For cloud and platform teams, this is often easiest to operationalise when the service principal is folded into the wider identity programme rather than handled as a separate exception. Non-human identity fundamentals, NHI lifecycle management, and IAM and IGA basics all reinforce the same operational point, that access reviews and entitlement ownership must cover machine-side identities too.
Risk and Threat Considerations
Unmanaged service principals create durable exposure because they often retain authority after the original human compromise is closed. Attackers value them because they can bypass MFA, survive password resets, and continue operating through tokens, certificates, or app secrets that are rarely watched as closely as user sessions.
Failure mechanism: A compromised user, admin workstation, or vendor integration reaches service principal credentials or consented permissions, then uses that delegated authority to access data, impersonate workloads, or establish persistence.
Impact: The attacker can move from workforce compromise into application-level access, extend dwell time, and retain access even after the initial human account is remediated.
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 SP 800-53 Rev 5 sets the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-01 — Improper Offboarding | Service principals outliving their business need is an offboarding failure. |
| NHI-02 — Secret Leakage | Credential rotation is needed because leaked app secrets expose service principals. | |
| NHI-05 — Overprivileged NHI | The question centers on excess access that lets service principals become pivot points. | |
| Recommendation — Retire unused service principals promptly and revoke their secrets, tokens, and roles. Rotate and vault service principal secrets, certificates, and tokens to reduce reuse risk. Enforce least privilege and recertify entitlements for each service principal on a fixed cadence. | ||
| NIST SP 800-53 Rev 5 | IA-9 — Identification and Authentication (Service and Device Accounts) | Service principals are service accounts that must authenticate as first-class identities. |
| AC-2 — Account Management | Ownership, lifecycle, and recertification are account management requirements for service principals. | |
| IA-5 — Authenticator Management | Credential rotation is central because service principals rely on managed authenticators. | |
| Recommendation — Apply service-account authentication controls and manage their authenticators explicitly. Inventory, review, and disable service principals that no longer have a valid business need. Rotate, protect, and revoke service principal credentials according to a defined lifecycle. | ||
Practitioner Guidance
What to verify: Every service principal should have a named owner, a documented purpose, an expiry or review date, and a clear map of the permissions it actually needs. If you cannot explain why the identity exists, it is already a governance gap.
Decision rule: If the principal can touch production data, secrets, or administrative APIs, treat it like a privileged identity for review, rotation, and exception handling. If it is dormant or undocumented, prioritise retirement before expansion of monitoring scope.
Practitioner takeaway: The control objective is not to separate users from service principals, but to make both equally governable so that delegated access cannot become a hidden persistence layer.
Related resources from NHI Mgmt Group
- What is the difference between attack surface management and NHI governance?
- How should security teams govern Active Directory service accounts?
- What makes GenAI usage part of the same secrets problem?
- How should security teams reduce identity risk when IAM tools cannot show the full attack surface?