Zero trust vs traditional security models for privileged access

At a glance

What this is: This is Keeper Security's explanation of how zero trust differs from traditional security models, with the key finding that privileged access becomes safer when trust is never assumed and access is continuously verified.

Why it matters: For IAM, PAM, and NHI practitioners, the article is a reminder that perimeter-based trust models leave too much standing access in place for modern cloud and remote environments.

Context

Traditional security models assume that identity can be trusted once it is inside a network boundary, which makes access control depend more on location than on verification. That model was built for perimeter-era environments, but it becomes brittle when users, devices, cloud services, and privileged sessions move continuously across environments.

Zero trust replaces that perimeter assumption with continuous verification, minimum necessary access, and stronger monitoring of privileged activity. In practice, the identity governance question is not whether access exists, but whether every request, session, and privilege level is explicitly justified in the moment.

For privileged access programmes, that shift is especially important because a compromise inside a trusted perimeter can quickly become lateral movement, excessive access, and weak containment. The article's core argument is that zero trust changes the operating model for PAM, not just the terminology.

Key questions

Q: What breaks when traditional privileged access still assumes users inside the network can be trusted?

A: The model breaks when internal placement becomes a substitute for verification. Once an account or device is trusted by default, excessive access, poor segmentation, and weak monitoring let a single compromise expand into lateral movement and broader data exposure.

Q: Why do privileged service accounts increase data breach risk in Zero Trust models?

A: Privileged service accounts often hold broad, persistent access that bypasses the containment benefits Zero Trust is trying to create. If those accounts are not scoped tightly, an attacker who steals one credential can reach data paths, administrative functions, or adjacent systems that should have remained isolated.

Q: How do teams know whether zero trust controls are actually reducing privilege?

A: A useful test is whether access disappears when the work is done. If privilege remains active after the task, the programme is monitoring access rather than reducing it. Teams should look for auto-expiry, resource-level scoping, and revocation that happens by design instead of manual cleanup.

Q: What should organisations do when a privileged session can reach too many internal systems?

A: They should treat that as a segmentation failure, not just an account issue. The right response is to narrow the resource boundaries, reduce standing access, and make sure one admin credential cannot traverse the environment unchecked.

Technical breakdown

Implicit trust in perimeter-based privileged access

Traditional security models treat the internal network as a trusted zone, so access decisions are heavily influenced by where a user or device connects from. That works only when the environment is relatively static. Once cloud services, remote work, and privileged administration are part of the picture, location-based trust creates broad access paths that are difficult to contain after compromise. The core weakness is not authentication alone, but the assumption that internal placement is a meaningful proxy for legitimacy. In identity terms, that makes privilege persistent, broad, and difficult to challenge after the initial login.

Practical implication: replace location-based privilege decisions with identity-bound access rules and session controls.

Continuous authentication and least privilege under zero trust

Zero trust changes the access model by requiring every request to be verified, not just the first one. That means identity, device posture, context, and behaviour all matter at decision time. Least privilege is the second half of the model: users and devices should receive only the permissions required for the specific task, not the broad access that traditional models often grant by default. In PAM terms, this is where JIT access, role scoping, and time-bound privilege reduce the amount of standing access that attackers can abuse if credentials are stolen or a session is hijacked.

Practical implication: enforce task-scoped access so privileged rights expire when the work ends.

Monitoring, segmentation, and lateral movement control

The article correctly ties zero trust to monitoring and segmentation because those controls determine whether a compromise stays small or spreads. Traditional security models often log too little and segment too loosely, which means suspicious activity can remain hidden while an attacker moves through shared trust zones. Under zero trust, privileged actions should be observable, and resource boundaries should be narrow enough that access to one system does not imply access to many others. That changes the defensive value of PAM from simple credential control to containment architecture.

Practical implication: segment privileged resources and alert on unusual privileged session behaviour.

Threat narrative

Attacker objective: The attacker aims to turn one legitimate access path into broader internal reach, exposing more systems and data than the original login should permit.

1. Entry occurs when a user or device gains access inside a trusted perimeter, often through valid credentials or a permitted connection path.
2. Escalation follows when the internal trust model grants broad privileges beyond the task actually being performed.
3. Impact emerges when the same trust zone allows lateral movement across systems, expanding the compromise beyond the initial account or device.

Breaches seen in the wild

• BeyondTrust breach 2024: A stolen BeyondTrust Remote Support API key let a China state-sponsored actor reset accounts and reach US Treasury workstations in 2024.

Read and download The State of NHI & AI Agent Breach Report 2026, covering 200+ breaches impacting Non-Human Identities including AI Agents.

NHI Mgmt Group analysis

Implicit trust is the governance flaw that zero trust is designed to remove. Traditional privileged access models assume that once identity crosses a boundary, trust can be extended operationally. That assumption no longer holds in distributed environments where the useful security unit is the session, not the perimeter. Practitioners should read this as a governance reset, not a tool discussion.

Privileged access is where zero trust becomes operational, not rhetorical. The article makes clear that least privilege, continuous verification, and segmentation only matter when they are applied to high-risk accounts and admin workflows. That is why PAM is not an adjacent control here. It is the mechanism that turns zero trust from a policy statement into enforceable privilege discipline.

Standing privilege is the wrong default for modern access governance. The combination of JIT access, revocation after task completion, and tighter session monitoring reflects a deeper shift in how access should be authorised. For identity programmes, the decisive question is no longer who is inside the network, but whether any privilege exists longer than the task that justified it.

Zero trust validates NHI governance assumptions that traditional security never had to test. The same continuous verification logic that constrains human privileged users also applies to service accounts, tokens, and machine-to-machine access. When identities are non-human, the governance challenge becomes whether the access path can be bounded, observed, and revoked with the same discipline as human admin access.

Identity blast radius is now the metric that matters. The article's strongest implication is that segmentation, monitoring, and least privilege are really about limiting how far one compromised credential can travel. That is a PAM and IAM design problem, but also an NHI governance problem wherever shared trust still exists.

From our research library:

• 90% of IT leaders say properly managing NHIs is essential for a successful zero-trust implementation, according to the Ultimate Guide to NHIs.
• Read next: Just-in-Time Access and Zero Standing Privilege Guide

What this signals

Identity blast radius is the real control variable: when privileged access is too broad, the question is not whether a compromise happens but how far it can travel before containment starts. Zero trust only changes outcomes when the access path is short-lived, tightly scoped, and observable across the full session.

The same access discipline increasingly has to cover human admins, service accounts, and automated workflows. That means PAM teams and NHI owners cannot treat least privilege as a separate programme, because the same standing-access problem appears across all three identity types.

Practitioners should expect zero trust language to keep converging with privilege governance, segmentation, and session monitoring. The organisations that benefit most will be the ones that stop treating perimeter removal as a network project and start treating it as an identity control redesign.

For practitioners

• Rebuild privileged access around explicit verification Replace perimeter-based trust assumptions with access decisions that evaluate identity, device context, and session risk at every privileged request.
• Scope privileged roles to task-level access Use role design and JIT provisioning so administrators and operators only receive the permissions needed for the current task, then lose them automatically.
• Segment privileged resources by blast radius Separate sensitive systems and admin functions so compromise of one account does not imply broad movement across the environment.
• Increase monitoring on privileged sessions Track admin activity, unusual access times, and changes in behaviour so security teams can detect misuse before it spreads across the estate.

Key takeaways

• Traditional security models still assume trusted placement inside the network, and that assumption creates broad access that is difficult to contain after compromise.
• Zero trust shifts the control point to continuous verification, least privilege, and tighter segmentation so one credential cannot move freely across systems.
• PAM becomes the practical enforcement layer for zero trust because it limits how long privileged access exists and how far it can reach.

Key terms

• Zero Trust: A security model that assumes no identity, human or non-human, should be trusted by default, even inside a network perimeter. Every access request must be verified, authorised, and continuously validated.
• Privilege Access Management: Privilege Access Management is the discipline of controlling and monitoring elevated access to critical systems and data. It governs how privileged accounts, credentials, sessions, and commands are issued, used, recorded, and revoked, so administrative power is limited, traceable, and aligned to policy, risk, and operational need.
• Least Privilege: A security principle requiring that every identity, human or non-human, is granted only the minimum permissions necessary to perform its function. Least privilege is the single most effective control for reducing NHI blast radius.
• Network Segmentation: Network segmentation divides traffic and resources into controlled zones so access can be restricted between groups, systems, or applications. In remote access design, segmentation limits what a connected user or workload can reach after authentication, which reduces lateral movement and shrinks blast radius.

Deepen your knowledge

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