Least Privilege Definition: How The Principle Works And Implementation Best Practices

One of the most fundamental and critical components of an effective cyberdefense strategy is access control, which limits and monitors who have access to sensitive data and systems in an organization. Access control also involves controlling what kinds of data and applications individuals access, under what conditions, and for what purposes. 

Many information security experts recommend controlling access via the principle of least privilege (PoLP). But what exactly does that mean? 

Below, we’re breaking down the definition of least privilege. Then, we’ll discuss the benefits of using least privilege, how to implement it, and helpful solutions to challenges you may face along the way.

What is the principle of least privilege?

The principle of least privilege states that the least amount of access an individual needs to uphold their responsibilities should define the extent of their access rights or permissions. 

So, rather than defaulting to open access to sensitive data, organizations should tightly control it. This means starting from a conceptual frame where nobody has any access and then adding privileged accounts when needed.

Sometimes known as the principle of minimum privilege or principle of least security, PoLP works by restricting a user's ability until proof is given that the user absolutely needs access to a specific task or function critical to operations.

Some experts argue that least privilege is the most important element of an effective cyberdefense. This is critical to advanced approaches such as Zero Trust Architecture (ZTA), which assumes the least privileges possible in all contexts and defaults to restricting access for all parties, irrespective of who they are.  

Least privilege vs. “need to know”

Another system that functions similarly to and in conjunction with PoLP is limiting access by “business need to know.” In these configurations, privileged users’ account functions are similarly tied to their responsibilities. 

In many cases, the need to know is specifically tied to an individual’s role, such that all users with a particular job title or in a given department may have privileged accounts until they’re moved.

One area in which need to know is especially important is compliance. The Payment Card Industry Data Security Standard (PCI DSS), which applies to most entities that process credit card information, specifically requires restricting access to cardholder data by business need to know (per Requirement 7). Several other sub-requirements also explicitly require the least privilege as a basis for or final test of secure access.

In practice, all access should abide by both least privilege and need to know.

How the least privilege principle works

There are many ways to implement PoLP access control. The basic premise is that users accessing information from company-owned or personal devices have limited capabilities based on what they need to do their jobs. 

Top methods include:

• Minimization of access rights: Users need to have their access capabilities restricted to the minimum amount possible to do their jobs effectively.
• Role-based access control (RBAC): Privileges can be associated with specific job descriptions or responsibilities and only granted if a user possesses them.
• Just-in-time access (JIT): Users are granted access and/or authorization upon request only if deemed appropriate and only for a finite amount of time.
• Need to know: While the need to know is distinct from least privilege (see above), it can be used as an attribute to define and restrict privileges.

PoLP focuses on preventing an abundance of superuser accounts that have access to all or most sensitive data in a system. Any such accounts can become liabilities in the event of a breach, so it’s best to keep privileges to a minimum.

Benefits of the least privilege principle

As noted above, access control is one of the most critical elements of an effective cyberdefense, and PoLP, in particular, is one of the best ways to enact access control.

Here are some of the top advantages provided by PoLP access control:

• Minimizing the attack surface: When users have fewer access points and pathways, so too do potential attackers—there’s less potential for compromise.
• Limiting the spread of malware: An abundance of access makes malware and viruses easier to spread; restricting access limits their possible reach.
• Improving overall operations: Users are tunneled toward mission-critical tasks more efficiently, with fewer threats to slow down operations.
• Meeting regulatory guidelines: Several regulatory frameworks explicitly require least privilege access, and it helps meet other mandates indirectly.
• Guarding against human risks: Least privilege lessens the scope of social engineering risks by minimizing the access a compromised account can have.
• Reducing overall resource costs: Preventing unauthorized access to data makes it less likely to be stolen, leading to less ransomware fees, fines, and more.

Looking closer at cost savings, access control is one of the best ways to prevent the exorbitant expenses of a data breach. IBM has found that the average cost of a data breach in 2023 was $4.88M, up 10% since 2022. Making breaches less likely and less impactful may be the biggest reason to limit access by the least privilege.

Best practices for implementing least privilege

The principle of least privilege does not automatically absolve organizations from cyber risks. Organizations need to integrate it effectively and intentionally to maximize its benefits.

Here are some best practices to keep in mind when implementing PoLP access:

• Auditing current kinds and levels of access: Create a baseline on which to improve or stabilize when controlling access via the least privilege principle.
• Carefully defining an approach to access: Define the general guardrails and expectations for access control, like which assets are most critical to protect.
• Drafting and disseminating an access policy: Create a policy stipulating which controls are to be used and how to define and operationalize privilege.
• Communicating with all stakeholders: All team members, especially leaders, need to know what least access is and what they need to do.
• Establishing user roles and responsibilities: All team members also need to be educated and trained on what they need to do (and how) to secure access.
• Establishing processes for regular review: Schedule assessments at regular intervals and establish protocols for auditing systems after security events occur.
• Implementing managed access solutions: Work with a trusted provider to implement hardware- or software-level access control and monitoring.

Even with measures like these, there are inherent obstacles when managing privileged and non-privileged accounts, especially at scale.

Common pitfalls in least privilege implementation

Some of the biggest challenges to effective PoLP access control involve breakdowns in communication. For example, failing to notify staff about their access privileges can lead to friction, especially amongst the least-privileged user accounts. 

It can be hard for them—and their managers—to navigate a wide variety of apps and programs without knowing exactly where they’re allowed to be, for what purposes, and why.

Similarly, there’s a risk of poor or out-of-date roles and responsibilities. For example, if employees change departments or gain new responsibilities, there’s a potential for privilege creep to grant them additional access they no longer require. Or, they may be stuck without proper access for a prolonged period, grinding operations to a halt.

One of the best ways to solve these and other issues of user access management is to implement AI and ML tools to automate as much as possible. You can assign, revoke, and manage privileged use via automated monitoring and reporting tools.

Tools for implementing the least privilege principle

Given the many approaches to least privilege access control, many tools and solutions can empower it. Here are some of the best options:

• Auditing and monitoring tools: Monitoring and visibility tools that transparent logins and user behaviors are a boon to access control. Any ability to step up security or revoke access if suspicious behavior is a plus.
• Permission management software: Permissions function similarly to privileges but are more often associated with one-time authorization rather than an account’s right or ability to access data and systems at all times.
• Privileged access management (PAM) software: These robust software suites are all-in-one solutions that streamline PoLP access management and integrate across on-premise and remote software and hardware connections.

Ultimately, the best privileged access management software makes it easy to prevent unauthorized access and allow required access. 

Learn more about powerful PAM software

The principle of least privilege is one of the most effective ways to implement access control across an organization. It minimizes risk by reducing access to the minimum amount possible. This prevents cybercriminals from abusing unnecessary or unmonitored account privileges and makes it easier to spot and stop attacks.

Our PAM software offers all the above benefits while mitigating the pitfalls with precise control, dynamic response, frictionless login, and unparalleled visibility. It streamlines access control with optimal security and UX.

Learn more about ConnectWise Access Management today!