API security best practices are really identity governance

At a glance

What this is: This is a StrongDM analysis arguing that API security problems are fundamentally identity governance problems, especially where authentication, token handling, access scope, and logging are weak.

Why it matters: It matters because IAM, PAM, and NHI teams often own the controls that determine whether APIs leak data, overexpose permissions, or stay governed across their lifecycle.

Context

API security is the control layer that decides who or what can call an API, what data it can reach, and how that access is observed. When authentication, authorisation, and logging are weak, the API becomes a direct path to sensitive data rather than a governed interface.

The governance gap is not API volume alone but the identity and access model behind it. For IAM and NHI programmes, APIs are where token scope, third-party access, and lifecycle discipline become visible failure points.

StrongDM’s article treats API security as an access governance problem first and a technical implementation problem second. That framing is typical of organisations that have many interfaces but inconsistent identity controls across them.

Key questions

Q: What breaks when API authentication is weak or token governance is missing?

A: The API stops behaving like a controlled interface and starts behaving like a standing access path. Weak authentication and poorly governed tokens let callers appear legitimate while bypassing the business intent behind the endpoint, which increases the chance of data exposure and unauthorised function use.

Q: Why do overbroad API permissions increase breach risk so quickly?

A: Because an authenticated caller may still receive data or functions it never needed. When object-level and field-level access are not constrained, a compromise of one token or service account can expose far more than the original request should have allowed.

Q: What are the signs that API governance is failing at runtime?

A: Common signs include undocumented endpoints, duplicated ownership, inconsistent responses, rising retry loops, and frequent discovery of APIs that are not in the catalogue. Those signals show that the live estate and the formal control model no longer match. Once that happens, security and reliability teams are managing assumptions instead of actual behaviour.

Q: How should teams govern APIs that are used by service accounts and automation?

A: Treat those API paths as part of the identity estate. Inventory the service accounts, tokens, and delegated applications that can reach sensitive endpoints, apply least privilege to each one, and retest whenever a workflow or payload changes. That prevents machine identities from inheriting broad access by default.

Technical breakdown

Broken API authentication turns tokens into standing access

API authentication is the mechanism that proves a caller is entitled to use an interface. In practice, this often depends on bearer tokens, API keys, or delegated credentials that act like portable proof of identity. If those credentials are weakly issued, over-scoped, or not tied to strong lifecycle controls, the API becomes a standing access path rather than a governed one. OAuth can improve the model, but only when token issuance, validation, and revocation are enforced consistently across services and environments.

Practical implication: Treat API authentication as credential governance, not just login design.

Excessive data exposure is an authorisation failure, not just a payload problem

APIs often return more data than the caller needs because the server trusts the request shape instead of enforcing least privilege at the object and field level. That is an identity and authorisation issue, because the caller may be authenticated yet still receive records, attributes, or functions beyond its business purpose. Zero Trust thinking applies here: access should be explicit, narrow, and continuously constrained, especially where third-party applications or service accounts consume the API.

Practical implication: Review API responses for overbroad object and field access, not only for transport security.

Logging and inventory are the controls that expose API abuse windows

If teams cannot inventory APIs or monitor authentication failures, unusual call patterns, and deprecated interfaces, they lose the ability to see misuse early. The article’s emphasis on older APIs, default configurations, and limited logging reflects a common failure mode: the exposed interface outlives the control that was supposed to govern it. In identity terms, this is lifecycle drift. A token, endpoint, or permission remains active after the business need has changed.

Practical implication: Use logging and inventory to find API endpoints that still behave as if their access model never changed.

Threat narrative

Attacker objective: The attacker wants unauthorised access to sensitive data or operational functions through a trusted application interface.

1. Entry occurs through broken API authentication, weak token handling, or misuse of deprecated interfaces that still accept requests.
2. Credential or token abuse lets the attacker act as an authorised caller and reach data or functions the interface should not expose.
3. Escalation happens when the API returns excessive data, accepts overbroad requests, or lacks logging strong enough to surface misuse quickly.
4. Impact is unauthorised access to sensitive data, degraded trust, and breach persistence until the API or token path is corrected.

Breaches seen in the wild

• Dropbox Sign breach 2024: A compromised back-end service account gave attackers Dropbox Sign customer data, including API keys, OAuth tokens and MFA information.
• McHire default password flaw 2025: A forgotten test admin account with the password 123456 and an API flaw exposed McDonald's McHire applicant records to researchers.

Read and download The State of NHI & AI Agent Breach Report 2026, covering 150+ breaches impacting Non-Human Identities including AI Agents.

NHI Mgmt Group analysis

API security is identity governance in a different wrapper: The article is right to frame API security around authentication, access control, and logging, because those are governance functions first and technical functions second. APIs become breach paths when teams treat tokens, scopes, and service access as implementation detail rather than governed identity state. The implication is that API risk belongs in IAM and NHI operating models, not in a separate security silo.

Excessive data exposure is usually a policy failure, not a code defect: When an API returns too much data, the core issue is that the interface has no enforced minimum-necessary access model. That is the same control logic used in least privilege, only applied to machine-to-machine access. Practitioners should recognise this as authorisation drift, not just poor response design.

Logging becomes an identity control when the caller is non-human: API abuse is harder to see when service accounts, tokens, and third-party clients share similar access patterns. That makes inventory, auditability, and revocation central to the control model. The field should stop treating observability as an afterthought and treat it as evidence that the identity lifecycle is still under governance.

API lifecycle and identity lifecycle are the same problem at different layers: The article’s advice to identify old APIs, maintain them, and remove them maps directly to offboarding logic. Endpoints, keys, and delegated permissions all need a retirement path. In practice, unmanaged API retirement is just another form of stale identity persistence.

OWASP API Security Top 10 is relevant here, but the deeper lesson is access governance: The main failure patterns the article names, broken authentication, excessive exposure, misconfiguration, and weak monitoring, all sit inside a broader governance model. Teams that fix only the endpoint without fixing entitlement scope will keep rediscovering the same breach pattern. Security teams should align API work to access governance, not just application hardening.

From our research library:

• More than 80% of enterprises will have used generative AI APIs or deployed GenAI applications by 2026, up from 5% in 2023, according to Gartner.
• Read next: Ultimate Guide to NHIs — What are Non-Human Identities

What this signals

API security is becoming an identity lifecycle problem: The critical failure is not simply that APIs exist, but that their credentials, scopes, and owners often outlive the business purpose they were created for. Teams should expect more incidents where the weak point is delegated access rather than the endpoint itself.

Access scope is the real control plane: When APIs are used by service accounts, third-party integrations, and automated workflows, least privilege has to be enforced at issuance time. Waiting to review access after deployment leaves too much room for stale tokens and overbroad permissions to persist.

Machine-to-machine access needs explicit governance: APIs are where NHI discipline becomes operational. If the inventory is incomplete or the revocation path is slow, the organisation has not secured the interface in any meaningful sense.

For practitioners

• Map APIs to their owning identities Build an inventory that ties each API to the service account, token issuer, or application identity that can call it. Include deprecated endpoints and third-party integrations so stale access does not survive the interface it was meant to support.
• Enforce narrow token scope Issue tokens and keys with the smallest viable permissions, and separate read, write, and administrative calls where the API design allows it. Revoke credentials when the business use case changes rather than waiting for an incident to expose the gap.
• Review object and field exposure Test API responses for excessive data exposure at the object and field level, especially where clients only need a subset of attributes. Treat overbroad responses as an authorisation defect, not just a privacy issue.
• Strengthen monitoring for misuse patterns Alert on repeated failures, unusual request volume, deprecated endpoint use, and calls from identities that no longer match the approved application inventory. Logging should show whether the access model is still aligned to reality.
• Define an API offboarding path Retire unused APIs, remove obsolete tokens, and close access paths that no longer have a business owner. Offboarding should cover both the endpoint and the identities that depended on it.

Key takeaways

• API security failures often begin as governance failures, especially when authentication, authorisation, and logging are not tied to identity lifecycle controls.
• The strongest attack paths involve weak token handling, excessive data exposure, and old interfaces that stay active after their business purpose changes.
• Teams should manage APIs, tokens, and service identities as one control surface so scope, ownership, and revocation stay aligned.

Key terms

• API Authentication: API authentication is the process of proving that a client, service, or application is allowed to call an API. It uses credentials such as keys, tokens, certificates, or signed assertions to verify identity. Strong API authentication reduces unauthorized access, supports auditability, and is a core control for machine-to-machine trust.
• Excessive Data Exposure: Excessive data exposure occurs when an API returns more information than the caller actually needs. The issue is usually a design and authorization problem rather than a coding typo, and it increases breach impact because a stolen credential can reveal far more data than intended.
• API Inventory: An API inventory is the authoritative record of what interfaces exist, who owns them, what data they touch, and how they are authenticated. For identity governance, it is the baseline control that makes review, monitoring, offboarding, and risk prioritisation possible across distributed services.
• Machine-to-Machine Access: Machine-to-machine access is communication where one software system or workflow reaches another without a human session in the middle. It is governed by credentials, policy, and trust boundaries, and it becomes risky when the access path is broad, poorly logged, or hard to revoke.

Deepen your knowledge

NHI governance, agentic AI identity, and machine identity lifecycle are core topics in our NHI Foundation Level course, the industry's only accredited NHI security programme. If you are building or maturing an IAM programme, it is worth exploring.