Zero trust vs least privilege: understanding the differences

Why do zero trust and least privilege matter in modern security?

Today’s attackers don’t rely on one trick to get in. They can exploit weak passwords, unsecured devices, misconfigured cloud apps, and even unsuspecting employees. Once inside, they move laterally until they reach valuable data, critical systems, administrative credentials, or any other valuable assets.

Zero trust and least privilege help close these gaps in different ways. Here are some trends that make implementing both more important than ever:

​The research backs this up:

• ​74% of breaches involve the human element, including stolen credentials or social engineering (Verizon DBIR 2023).

• ​80% of organizations admit they struggle with excessive access privileges, which attackers exploit once they’re inside (Ponemon Institute).

​Zero trust vs least privilege isn’t a matter of choosing one or the other. Both are required to give leaders layered protection against modern threats.

What is zero trust security?

​Zero trust is a security framework built on a simple idea: never trust, always verify. Instead of assuming that users, devices, or applications within the network are safe, zero trust treats every access attempt as potentially risky.

​Zero trust is designed to address today’s most common attack vector: identity. In practice, it strengthens defenses against stolen credentials and identity-based attacks, which continue to be the leading cause of breaches.

​The framework was popularized in the early 2010s as organizations transitioned to cloud computing and remote work environments, where traditional perimeter defenses, such as firewalls, struggled to keep up. Today, zero trust is seen as a foundational approach for modern cybersecurity.

​Key elements of zero trust include:

​In practice, zero trust strengthens defenses against identity-based attacks—the most common entry point for breaches.

​By reducing unnecessary permissions, least privilege prevents insider misuse and limits the impact of compromised accounts.

Need to know vs least privilege in access control

​The terms need to know vs least privilege are often used together, but they focus on different aspects of access control.

In practice, the two approaches complement each other. Need to know prevents information from being shared too broadly, and least privilege prevents users from taking unnecessary actions with the information or systems they have access to.

​Together, they build stronger defenses against insider threats and credential-based attacks. In cybersecurity, least privilege builds on need-to-know principles by adding a layer of restriction around what users can do once they’ve been granted access.

Comparing zero trust privilege and the least access privilege model

​Zero trust and least privilege both strengthen access control, but they operate at different scopes.

​Zero trust is a comprehensive security framework that governs how access is verified across the entire environment. Least privilege is a specific principle within that framework, focused on restricting how much access a verified user or device actually receives.

Least privilege vs zero trust in cybersecurity implementations

​Zero trust and least privilege share the same goal: reducing risk by controlling access. But they reinforce each other in different ways, and the strongest security comes when both are applied together.

​Think of it this way:

• Zero trust is the gatekeeper. It decides whether someone can approach the door at all, using identity verification, device health checks, and continuous monitoring.

• ​Least privilege is the room key. Once inside, it limits where a user can go and what they can touch, ensuring access is tightly aligned to their role.

For example, imagine a contractor logging in remotely to update a cloud application.

• Zero trust validates their identity with MFA, checks that their laptop is patched, and verifies the login is coming from an approved location.

• ​Least privilege then restricts their account to the single app they need, blocking access to sensitive data, internal HR tools, or admin consoles.

​If their credentials are stolen, the attacker faces both hurdles: they can’t get through the initial checks easily, and even if they do, their reach is tightly confined.

​Zero trust and least privilege aren’t competing strategies; they’re layers. Zero trust sets the standard of “never trust, always verify,” while least privilege enforces “only what’s necessary, nothing more.” Combined, they create guardrails that protect hybrid environments, simplify compliance with frameworks like NIST and HIPAA, and reduce the blast radius of a breach.

​Zero trust implementation often requires:

How to implement zero trust and least privilege approaches

​Combining zero trust and least privilege creates a layered defense that secures both access requests and permissions. Here are four steps to get started:

Strengthen your organization’s security with Duo’s approach to zero trust

Zero trust and least privilege work best when they’re applied together, and identity is the thread that connects them. Duo helps organizations combine these principles into a practical, unified strategy.

With Duo, you can:

• Verify identity and device health before granting access, ensuring only trusted users on secure devices connect.

• Enforce adaptive MFA that challenges users based on context, reducing friction while maintaining strong security.

• Support least privilege by pairing strong authentication with role-based and just-in-time access controls.

Enable continuous monitoring through integrations that feed real-time signals into your security operations.

Count on a security model that prevents unauthorized access and limits the impact of compromised accounts. By addressing who gets in and what they can do once inside your network, Duo simplifies the path to adopting zero trust in hybrid and cloud environments.

Start your free Duo trial today and see how identity-driven security can protect your organization!