Vendor access gaps are undermining zero trust identity controls

At a glance

What this is: This is an analysis of why zero trust architectures fail when vendor access is left outside consistent privileged access governance.

Why it matters: It matters because IAM, PAM, NHI, and contractor governance all break down when third-party access is treated as an exception instead of part of the identity model.

By the numbers:

• Only 36% of health IT leaders say their organisations have a privileged access strategy applied consistently enterprise-wide.
• Imprivata says vendor privileged access management can improve IT efficiency by as much as 88% in some cases.

👉 Read Imprivata's analysis of vendor access gaps in zero trust

Context

Zero trust is a security model built on continuous verification, least privilege, and explicit access decisions rather than implicit network trust. In practice, the model weakens when organisations secure employees but leave vendors, contractors, and fourth parties outside the same control plane, because those identities often reach sensitive systems through separate approval, authentication, or remote access paths.

Vendor access is not a side issue in identity governance. It is a governance blind spot that links IAM, PAM, and non-human identity management, because the same enterprise often treats internal users, service accounts, and external collaborators under different rules. When that split persists, zero trust becomes a perimeter strategy with better branding rather than a consistent access model.

Key questions

Q: How should security teams govern vendor access in a zero trust programme?

A: They should treat vendor access as part of the core identity model, not as a separate remote support exception. That means applying the same authentication, approval, least privilege, and session oversight controls used for internal privileged users, then reviewing whether external access is still justified on a task-by-task basis.

Q: Why do vendors and contractors weaken zero trust if they are not included in PAM?

A: Because zero trust depends on consistent policy enforcement across every identity that can reach sensitive systems. If vendors keep standing access, shared credentials, or separate approval paths, the organisation preserves implicit trust for the very users most likely to expand the attack surface.

Q: What breaks when third-party access is excluded from privileged access reviews?

A: Auditability breaks first, followed by entitlement accuracy and offboarding discipline. Without regular reviews, organisations cannot tell whether a vendor still needs access, which credentials remain active, or whether the relationship that justified access still exists.

Q: How can organisations reduce vendor access risk without stopping external work?

A: Use task-scoped access, credential vaulting, MFA, and explicit expiration dates so vendors can do the job without retaining broad standing privilege. The goal is to narrow access windows and make every external entitlement easy to justify, observe, and revoke.

Technical breakdown

Why vendor access breaks zero trust enforcement

Zero trust assumes every access request is evaluated in context, with no implicit trust based on network location or relationship. Vendor access breaks that model when external users retain broad standing entitlements, are routed through exception workflows, or rely on shared remote access paths that bypass the same verification logic used for employees. The architectural failure is not authentication alone. It is inconsistent policy enforcement across identity populations, which creates a privileged side door even in otherwise mature environments.

Practical implication: map vendor identities into the same access policy and review model as internal privileged users.

Privileged access strategy across contractors and third parties

A privileged access strategy is only effective when it covers every identity that can reach sensitive systems, including vendors, managed service providers, and other third parties. In many organisations, PAM is applied to employees but not extended to external operators, which leaves credential vaulting, session control, and approval logging unevenly enforced. That creates an identity governance gap rather than a tooling gap. The risk is not just misuse, but lack of auditability when a vendor account is the path into a critical environment.

Practical implication: extend PAM and vendor privileged access management controls to third-party accounts, sessions, and credentials.

MFA and credential vaults are necessary but not sufficient

MFA and credential vaults reduce exposure, but they do not by themselves solve the governance problem created by overly broad or persistent vendor access. If access scope is wrong, strong authentication merely proves the wrong identity can still enter the wrong system. Zero trust requires the combination of identity verification, task-scoped entitlements, and rapid removal of stale access. Without that lifecycle discipline, vendors keep access longer than the work justifies, which is exactly where attack surface accumulates.

Practical implication: pair MFA with least privilege, access expiry, and credential rotation for every external identity.

NHI Mgmt Group analysis

Vendor access is the zero trust exception that reveals the programme is not complete. Zero trust is supposed to erase implicit trust, yet third-party access is often treated as an operational carve-out. That carve-out is not a minor exception. It means the organisation has created a parallel trust model for the identities most likely to bypass internal control assumptions. The implication is that zero trust maturity must be measured by how consistently it governs external access, not by how broadly it is deployed internally.

Privileged access applied enterprise-wide is the real control benchmark. The statistic that only 36% of health IT leaders apply privileged access consistently across the enterprise shows the governance gap is structural, not isolated. When vendors sit outside that strategy, the enterprise loses uniform session oversight, entitlement review, and credential accountability. What fails is not just a control, but the assumption that privileged access can be managed safely in two different ways at once. Practitioners should treat vendor identities as first-class subjects in PAM and IGA.

Zero trust without vendor lifecycle governance becomes continuous verification without continuous accountability. A login can be rechecked in real time, but the relationship behind that login still needs lifecycle control. If vendor access is granted, renewed, and retired outside the same governance cadence as employee access, the organisation cannot prove who should still have access or why. That is where auditability, offboarding, and least privilege all drift apart. The implication is that vendor access must be governed as part of identity lifecycle, not as a separate remote access project.

VPAM is the named concept that closes the gap between third-party access and privileged control. Vendor privileged access management reflects the reality that contractor and supplier access has distinct approval, session, and revocation requirements. It is not a standalone product category so much as a governance pattern for external privileged users. Where VPAM is absent, zero trust often becomes a slogan layered over legacy access exceptions. Practitioners should align vendor access with the same entitlement, vaulting, and review discipline used for high-risk internal access.

From our research:

• 1.5 out of 10 organisations are highly confident in their ability to secure NHIs, compared to nearly 1 in 4 for securing human identities, according to The State of Non-Human Identity Security.
• Lack of credential rotation is cited as the top cause of NHI-related attacks by 45% of organisations, followed by inadequate monitoring and logging at 37% and over-privileged accounts at 37%.
• For a broader view of the breach patterns behind those failures, see The 52 NHI breaches Report for case-level analysis of exposure, persistence, and misuse.

What this signals

Vendor access is becoming the easiest way for zero trust programmes to fail quietly, because external identities are often governed by exceptions rather than policy. The practical signal is simple: if contractor and supplier access cannot be recertified, revoked, and logged with the same rigor as employee privilege, the architecture is already inconsistent. That gap now matters more as remote support, managed services, and third-party operations become normal operating dependencies.

External privilege debt: this is the accumulation of vendor accounts, shared credentials, and stale support paths that survive long after the original business justification has disappeared. The debt grows when lifecycle governance is split between procurement, operations, and security. Teams should expect the audit burden to rise unless they centralise external identity reviews and connect them to access expiry. See NIST Cybersecurity Framework 2.0 for the govern, identify, protect, detect, respond, and recover structure that helps align ownership.

Health IT environments are especially exposed because third-party access often reaches clinical and administrative systems through privileged channels that were designed for efficiency, not continuous oversight. That means the next maturity step is not another authentication layer alone. It is a governance model that makes vendor access observable, reviewable, and revocable on the same cadence as the rest of the identity estate.

For practitioners

• Extend privileged access coverage to vendor identities Inventory all vendor, contractor, and fourth-party accounts that can reach production, admin consoles, or sensitive data. Bring them under the same access review, approval, and session oversight process as internal privileged users.
• Apply task-scoped access expiry to external users Replace persistent vendor entitlements with access that expires when the task ends or the contract changes. Tie renewal to explicit business justification and remove standing access from dormant supplier accounts.
• Vault and rotate every third-party credential Store vendor credentials in a controlled vault and rotate them on a defined schedule, especially where remote support or shared admin access exists. Eliminate unmanaged passwords, tokens, and long-lived shared secrets.
• Unify vendor access logging with PAM evidence Require session recording, authentication logs, and approval history for vendor access paths. Feed those records into the same audit and recertification process used for internal privileged access so exceptions are visible.

Key takeaways

• Zero trust loses much of its value when vendor access is governed as an exception rather than as part of the identity programme.
• The 36% enterprise-wide privilege strategy figure shows the problem is structural, not limited to one control family.
• Teams need unified vendor lifecycle governance, not just stronger authentication, if they want zero trust to hold in practice.

Key terms

• Vendor Privileged Access Management: Vendor Privileged Access Management is the set of controls used to govern external users who need elevated access into enterprise systems. It extends PAM discipline to contractors, suppliers, and managed service providers so their sessions, credentials, approvals, and revocation are visible and auditable.
• Zero Trust Architecture: Zero Trust Architecture is a security model that assumes no identity or network location is trusted by default. Access is granted only after continuous verification, explicit policy checks, and least-privilege evaluation, which means every identity population must be governed consistently for the model to work.
• Privileged Access Strategy: A privileged access strategy is the enterprise approach for controlling high-risk access across users, systems, and third parties. It defines how privileged accounts are approved, vaulted, monitored, recertified, and removed so that elevated access remains limited, traceable, and accountable.
• Third-Party Access Path: A third-party access path is any route by which a vendor or contractor reaches internal systems, including remote support tools, VPNs, shared accounts, and delegated admin sessions. These paths matter because they often bypass the same governance and review processes used for employees.

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 responsible for identity security strategy or NHI governance in your organisation, it is worth exploring.

This post draws on content published by Imprivata: Zero Trust Efforts Fall Short When Vendor Access Is Ignored. Read the original.