The principle of least privilege: what is it and why is it needed?

One of the most important concepts in information security is the principle of least privilege. In this post, we explore what it is, how it works, how adhering to this principle benefits businesses, and how to implement the principle of least privilege in practice.

How the principle of least privilege works

The principle of least privilege (PoLP) is also known as the principle of minimal privilege (PoMP) or, less commonly, the principle of least authority (PoLA).

The main idea is that access to resources in a system should be organized in such a way that any entity within the system has access only to those that the entity requires for its work, and no more.

In practice, this could involve different systems and different entities within a system. Either way, in terms of applying the principle of least privilege to enterprise security, this can be restated as follows: Any user of the organization’s information infrastructure should only have the right to access the data that is necessary for performing their work tasks.

If, in order to perform certain tasks, a user requires access to information they currently don’t have, their permissions can be elevated. This elevation can be permanent – if required by the user’s role, or temporary – if it’s only necessary for a specific project or task (in the latter case, this is called “privilege bracketing”).

Conversely, when a user no longer requires access to certain information for some reason, their permissions should be lowered in accordance with the principle of least privilege.

In particular, the principle implies that regular users should never be granted administrator or superuser rights. Not only are such privileges unnecessary for the duties of the average employee, but they also significantly increase risks.

Why is the principle of least privilege needed?

The principle of least privilege helps improve access management, and generally hardens the security of the company’s information infrastructure. Here are some of the important security objectives that can be achieved by applying the principle of least privilege.

1. Risk mitigation. By restricting access to the minimum necessary for users to perform their tasks, the likelihood of accidental or intentional misuse of privileges can be significantly reduced. This, in turn, helps lower the risks of successful perimeter penetration and unauthorized access to corporate resources.
2. Data protection. Limiting access helps protect confidential data. Users only have access to the data required for their work, thereby reducing the likelihood of their gaining access to sensitive information or, worse, causing its leakage or theft.
3. Minimizing the attack surface. Restricting user privileges makes it more difficult for attackers to exploit vulnerabilities and use malware and hacking tools that rely on the user’s privileges, thereby reducing the attack surface.
4. Localizing security incidents. If an organization’s network is breached, the principle of least privilege helps limit the scope of the incident and its consequences. Because any compromised accounts have minimal rights, potential damage is reduced, and lateral movement within the compromised system or network is impeded.
5. Identifying users responsible for an incident. Minimizing privileges significantly narrows down the circle of users who could be responsible for an incident. This speeds up the identification of those accountable when investigating security incidents or unauthorized actions.
6. Compliance with standards and regulations. Many regulatory requirements and standards emphasize the need for access control – particularly the principle of least privilege. Adhering to industry standards and best practices helps organizations avoid unpleasant consequences and sanctions.
7. Increasing operational efficiency. Implementing the principle of least privilege reduces risks for the organization’s information infrastructure. This includes reducing downtime associated with security incidents, thus improving the company’s operational efficiency.

How to implement the principle of least privilege in your organization

Implementing the principle of least privilege in an organization’s information infrastructure can be broken down into a few basic steps and tasks:

• Conduct an inventory of resources, and audit the access rights users currently have.
• Classify resources and create an access management model based on roles – each with specific rights.
• As a starting point, assign users roles with minimal rights, and elevate their privileges only if necessary for their tasks.
• Regularly conduct audits and review permissions – lowering privileges for users who no longer need access to certain resources for their tasks.
• Apply the principle of privilege bracketing: when a user needs access to a larger number of resources for a task, try to elevate their privileges temporarily – not permanently.

And don’t forget about other protective measures

Of course, applying the principle of least privilege alone isn’t enough to secure a company’s information infrastructure. Other measures are also required:

• Regular security audits.
• Timely software updates.
• Employee training on the basics of cybersecurity.
• Deploying reliable protection on all corporate devices.