What is the Principle of Least Privilege?

The Principle of Least Privilege is also commonly known in the cybersecurity community as Least Privilege Access (LPA). This concept in the security world essentially stipulates that there is a minimum amount of privilege – or access – granted to any entity that is a human user or automated process that needs permission to use an application to achieve its goals and which is also compliant with the organization’s risk goals.

What is Privilege Creep? 

Privilege creep is the process of losing control of the number of permissions a specific user maintains in order to do their job or to complete a task. Simply put, if a user no longer needs access to a certain application to do their job, then that permission should be revoked to maintain as secure of an environment as possible.

In such circumstances, certain users obtain and hold more permissions and higher levels of access than their current job roles or responsibilities actually warrant. This might happen if, for example, permissions are granted to access resources for a temporary work assignment of short duration, but are not subsequently disallowed when that work assignment comes to an end.

Similarly, a change of job responsibilities could lead to an aggregation of privileges and permissions the person no longer needs. Automating LPA can help to address challenges like privilege creep and also:

  • Prevention of misuse from privileged accounts
  • Added complexity from short-term cloud entitlements
  • Inconsistency across multiple cloud infrastructures
  • Accounts with excessive access permissions

Zero Trust vs. Principle of Least Privilege

The concept of zero trust primarily relies on verification of different methods. In this security scenario, a user will never be able to simply gain access without undergoing some type of verification check. The most common type of verification technology is multi-factor authentication (MFA). This usually comes in the form of inputting a hardware key, receiving an authenticating text message, and/or inputting a one-time code so they can gain access.

Least privilege, on the other hand, is a process by which a user is inherently trusted and verified for the length of time they’ll need access to the application or program – meaning they won’t have to overcome any security verification measures to gain access.

Why is Least Privilege Access Important? 

LPA is important because it helps to keep a network as secure as possible. It does this by limiting the number of permissions network users need to do their job. In this way, a specific user doesn’t end up with excessive permissions, but it’s often understandable how they could.

Network environments, particularly in large enterprises, are often extremely large in scale, and it’s not always easy to know the exact permissions users will need. Similarly, when you’re not quite sure what permissions a new user will need in the long run, it may be more convenient to over-provision in the off-chance they’ll require those permissions in the future.

If a user’s system – or endpoint – were to be compromised, a threat actor would have access to all of the user’s unnecessary escalated permissions. This could enable that threat actor to potentially enact a ransomware attack by leveraging stolen privileges to hop from system to system so they can easily scour the network and find desirable data to encrypt and exfiltrate.

Privilege creep happens to every security organization, and it can seem difficult – if not unfathomable – to hope to successfully manage excessive permissions at scale. Any solution to this problem needs to be able to establish a baseline of what normal activity looks like, which can be accomplished by tracking actual activity over a set period of time.

Once a normal baseline has been established, that normal activity can be correlated with the permissions granted to a given entity, and the permissions can be automatically adjusted to adhere to the organization's LPA guidelines.

What are the Benefits of Least Privilege Access? 

The benefits of LPA are vast. An identity and access management (IAM) program, a broader category concerning access under which the concept of LPA falls, is a critical component of any modern security program.

A key benefit in instituting the principle of least privilege is that it essentially locks down the network attack surface without causing a significant slowdown in productivity. Let’s take a look at some of the other benefits of a least privilege access model:

  • Limit damage: According to the Center for Internet Security (CIS), by governing the level of access for each user, system, and process, LPA can limit the potential damage from unsanctioned activities, whether intentional or unintentional.
  • Build into network segments: Network segmentation is already a great security measure to prevent total attack surface infiltration. Add to that the ability of LPA to be deployed across users building and securing those segments, and the network's defenses are optimized even further.
  • Maintain a clean environment: If a user is finished working on a project and simply wants to look back at it, LPA will deny that ability. A myriad of human errors due to unnecessary access is a great way to let attackers exploit vulnerabilities, spread malware, and cost the business money and reputation.

How to Implement Least Privilege Access

Teams can establish and manage LPA by setting the minimum privileges possible to achieve the organization's risk goals. They can also:

  • Proactively analyze cloud environments for excessive entitlements at scale. An effective solution should break down complex, multi-tiered IAM policies and analyze them within the context of an environment to simplify the process of finding and fixing excessive entitlements.
  • Continuously monitor as well as automate remediation of anomalous behaviors and excessive permissions. This is a critical way to stay on track when growing cloud operations. For example, in InsightCloudSec from Rapid7, teams can leverage pre-defined bot actions and specify the resources they’ll evaluate for excessive permissions.
  • Leverage identity analysis protocols to provide a unified view into identity-related risk across cloud environments, enabling security organizations to achieve LPA at scale.
  • Get their workforce ready to adopt LPA best practices. Most of us are used to jumping through some sort of identity verification hurdle to access things like bank information, healthcare portals, and educational tools for children. This semi-new normal societal behavior can help alleviate some of the friction implementing LPA business-wide might cause. However, implementations will look different for each organization, so it’s a good rule of thumb to over communicate to an employee base.

LPA is a never-ending process, requiring ongoing assessment of privilege levels against organizational roles and permissions. With over privileged account discovery, and some guided remediation, cloud infrastructure entitlement management (CIEM) tools can help organizations move toward a stronger security posture. 

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Least Privilege Access: Latest Rapid7 Blog Posts

Report: Gartner® Research: Cloud Infrastructure Entitlement Management (CIEM)