APIs expand attack surface and identity risk across modern systems

At a glance

What this is: This is a high-level explanation of how APIs became foundational to modern software and why their security exposure grows with their reach.

Why it matters: It matters because API ecosystems depend on secrets, service accounts, and delegated access, which places API governance squarely in scope for IAM, PAM, and NHI programmes.

By the numbers:

• 96% of organisations store secrets outside of secrets managers in vulnerable locations including code, config files, and CI/CD tools.
• NHIs outnumber human identities by 25x to 50x in modern enterprises.
• Only 5.7% of organisations have full visibility into their service accounts.
• 97% of NHIs carry excessive privileges, increasing unauthorised access and broadening the attack surface.

👉 Read Pynt's analysis of how APIs changed software integration and security risk

Context

APIs are the connective tissue of modern digital services, but every connection introduces an access path that must be governed. In practice, the risk is not just application exposure but the identities, tokens, keys, and service permissions that let systems talk to each other.

For IAM and NHI teams, the API problem is really a lifecycle problem: who created the credential, where it lives, who can use it, how it is revoked, and whether its privileges match the workload’s real function. That intersection is where API governance becomes identity governance.

The article treats APIs as an innovation enabler, which is typical. What is less often addressed in broad API commentary is that scale without identity controls converts integration speed into persistent access risk.

Key questions

Q: How should security teams govern API credentials in SaaS environments?

A: Treat API credentials as non-human identities with owners, purpose, scope, and expiry. The practical baseline is least privilege, short-lived access where possible, regular recertification, and behavioral monitoring for misuse. Inventory is necessary, but governance only works when teams can prove who authorized access, why it exists, and whether the integration still needs it.

Q: Why do APIs create identity risk for IAM and PAM programmes?

A: Because APIs rarely operate without credentials, and those credentials often outlive the service they support. If a token or key is over-privileged, compromise of one integration can expose many systems. IAM and PAM teams need to treat API access as delegated privilege, not just application plumbing.

Q: What do security teams get wrong about API perimeter controls?

A: They assume syntax inspection and request reputation are enough. In BOLA, the payload can be clean, the endpoint can be correct, and the token can be valid while the access decision is still wrong. The real control gap is the missing relationship check between identity and object.

Q: Which frameworks require stronger API governance and access control?

A: PCI DSS, GDPR, NIST SP 800-53, and Zero Trust guidance all expect organisations to know what they expose, limit access, and monitor use. For identity and security teams, the practical test is whether each API has a named owner, bounded access, and evidence of continuous control operation. If not, the framework requirement is only partially met.

Technical breakdown

API access paths and credential dependence

APIs rarely authenticate in the abstract. They rely on API keys, OAuth tokens, certificates, signed requests, or workload identities that prove one system may call another. That means every API endpoint becomes part of an identity and authorisation chain, not just a technical interface. If those credentials are embedded in code, copied into pipelines, or shared across environments, compromise can happen without any visible user login. The security question is therefore not only whether the API is exposed, but whether the surrounding identity controls limit what the calling system can do.

Practical implication: inventory API credentials as non-human identities and govern them with the same lifecycle discipline used for privileged accounts.

Why API sprawl becomes governance sprawl

API growth often outpaces control design. Teams create internal, partner, and public APIs across many services, and each one can introduce a different authentication method, permission model, and revocation process. This creates governance sprawl, where security teams can no longer answer basic questions about ownership, expiry, or blast radius. In identity terms, the problem is multiplied because each API may be backed by a distinct service account, token, or secret that needs its own lifecycle. The more distributed the architecture, the easier it is for stale access to persist.

Practical implication: require every API to have a named owner, a defined authenticator, and an enforced expiry or rotation policy.

API security and non-human identity control gaps

APIs are often treated as application plumbing, but the real control gap is usually NHI governance. If service accounts are over-privileged, secrets are long-lived, and revocation is inconsistent, an attacker who reaches one API may inherit broad downstream access. That is why API security intersects directly with Zero Trust and least privilege. In a mature model, authentication proves workload identity, authorisation is narrowly scoped, and standing access is minimised. The article’s broad innovation narrative is common; the missing control narrative is that innovation without identity governance leaves API trust assumptions intact.

Practical implication: align API authorisation with least privilege and eliminate standing credentials wherever automated access can be made ephemeral.

Threat narrative

Attacker objective: The attacker wants to turn a trusted application integration into an authenticated path for data theft, service abuse, or broader compromise.

1. Entry occurs when attackers discover exposed API keys, weak authentication, or over-trusted integration points in applications, code repositories, or CI/CD systems.
2. Escalation follows when stolen or mis-scoped credentials grant access to additional services, data stores, or administrative functions beyond the original API purpose.
3. Impact occurs when attackers use the trusted API path to extract data, trigger fraudulent transactions, or move laterally into connected systems.

NHI Mgmt Group analysis

API governance is identity governance once systems depend on secrets and delegated trust. The article describes APIs as a business enabler, but operationally every API call is a statement about who or what may act on behalf of a system. That makes API security inseparable from IAM, PAM, and NHI lifecycle management. The practitioner conclusion is simple: if you cannot govern the credential, you do not fully govern the API.

API sprawl creates a visibility gap that security programmes routinely underestimate. As integrations multiply across cloud, mobile, IoT, and chat systems, ownership and revocation often become unclear. This is where identity sprawl: the accumulation of unmanaged service identities, tokens, and permissions across many systems, becomes a measurable governance problem. The practical conclusion is that API inventories must include authenticator ownership, expiry, and privilege scope, not just endpoint lists.

Excessive privilege turns benign integration into a breach multiplier. When a single token can reach multiple backend services, the attacker’s first valid credential often becomes the most efficient route to lateral movement. That pattern is why least privilege and Zero Trust matter for APIs as much as for users. The practitioner conclusion is to treat every API permission as a blast-radius decision.

Broad API commentary usually celebrates speed, but the real control question is lifecycle. Credential issuance, rotation, revocation, and offboarding determine whether API access remains governable after deployment. In identity programmes, that means runtime governance cannot be an afterthought. The practitioner conclusion is to design API onboarding and offboarding as lifecycle processes, not one-time configuration tasks.

What this signals

Identity teams should expect API governance to merge further with NHI management. As more services rely on machine-to-machine authentication, the operational boundary between application security and identity security keeps shrinking. That means API ownership, credential inventory, and access review will become standard identity programme work, not a separate engineering concern.

Secrets exposure remains the clearest warning signal for API risk. When credentials live in code, config files, and CI/CD tooling, the control problem is no longer theoretical. Teams should pair inventory work with the NIST SP 800-53 Rev 5 Security and Privacy Controls guidance on authenticator management and access control, then enforce rotation and revocation as measurable outcomes.

Service account sprawl is a governance debt item, not just an architecture issue. The more APIs depend on persistent credentials, the more difficult it becomes to prove least privilege or to contain breach impact. In practice, that should push security leaders to classify API identities alongside other NHIs and bring them into periodic review and offboarding workflows.

For practitioners

• Map every API to an owning identity Create an inventory that links each API to its service account, token issuer, certificate, and business owner so revocation is always traceable. Use the inventory to identify orphaned integrations and stale access paths.
• Move secrets out of code and pipelines Eliminate hardcoded API keys in source repositories, configuration files, and CI/CD variables. Store secrets in governed systems with rotation, audit logging, and scoped access enforced by policy.
• Constrain API permissions to task scope Review each API’s effective permissions and remove broad access to downstream services that the workload does not need. Pair this with short-lived credentials where possible so access expires with the task.
• Build lifecycle controls for API offboarding Define a revocation process for applications, partners, and automation jobs so credentials are disabled when a service is retired, replaced, or no longer trusted. Include validation to confirm that access was actually removed.

Key takeaways

• APIs become security liabilities when their credentials, permissions, and ownership are not governed as identities.
• The scale problem is visible in secret sprawl and service account opacity, which makes compromise harder to detect and contain.
• API programmes should shift from one-time integration controls to lifecycle governance with rotation, revocation, and least-privilege enforcement.

Key terms

• API gateway: An API gateway is the enforcement layer that sits in front of backend services and decides how requests are authenticated, authorized, routed, logged, and rate limited. In partner ecosystems it functions as a control point for machine access, not just a traffic router, because it can unify identity and transport checks.
• Service Account: A special-purpose account used by applications, automated tools, or services rather than a human user to interact with systems, APIs, and infrastructure. Service accounts are a primary category of NHI and one of the most frequently exploited attack vectors.
• Secrets Sprawl: The uncontrolled proliferation of sensitive credentials — API keys, tokens, passwords, certificates — across codebases, cloud environments, CI/CD pipelines, and configuration files. In 2024, over 50 million leaked secrets were found on the dark web.

What's in the full article

Pynt's full article covers the operational detail this post intentionally leaves for the source:

• Examples of how APIs support mobile, IoT, chat, voice, and healthcare integrations in practice.
• The article's broader explanation of where APIs sit in modern software architectures and business models.
• The source's discussion of how API security fits alongside innovation goals without slowing development.
• The vendor's own framing of why API growth changes the way teams should think about software delivery.

👉 Pynt's full article expands on the role of APIs across mobile, IoT, chat, and healthcare systems.

Deepen your knowledge

NHI Foundation Level course, the industry's only accredited NHI security programme, covers NHI governance, machine identity security, and secrets management. It gives IAM and security practitioners a practical way to connect identity controls to modern service-to-service access.