The principle of least privilege is a concept in cybersecurity that emphasizes on limiting user and process access to a minimum required to perform their job duties. This principle is based on the idea that by limiting access to resources, the risk of unauthorized access, use, or disclosure is reduced.
In practice, this means that users should only be granted access to the specific resources and functions that are required for their job, and that their access should be regularly reviewed and adjusted as necessary. The idea is to provide just enough access for the user to perform their job, and no more. The principle of least privilege applies to Authorization in the AAA identity and access management model.
Access Authorization Process
Authorization is the process that grants a user approval to take certain action in the designated systems whether it is to view, modify, share, or delete data. Authorization is concerned with what the user is allowed to do.
The granularity of authorization is only as good as the sophistication of the system which supports the access approval decision-making process and enforcement of approved access.
The access approval process is designed to grant access based on the user’s role and job duties which is referred to the principle of least privilege, which states users, devices, programs, and processes which are interconnected or must access each other to communicate and take certain actions, should be granted just enough permissions to do their required functions.
The risk of excessive and unnecessary access as well as the risk of insufficient access to perform a certain task to accomplish a goal should not be overlooked. Excessive access rights beyond someone’s normal job functions create an opportunity for errors, accidents, and exploits which can affect the confidentiality, integrity, and availability of data and systems. Insufficient access or access rights not provided in a timely manner can also negatively affect business operations.
A much severe case is when a user is granted administrator or a root access to a system without any justification. The highly privileged access should be limited to just a few persons in an organization because if the account is infected with malware or access credentials are stolen, the intruder can inflict much greater damage than with limited access privileges.
When someone’s access is beyond that person’s required access to perform their job duties, then that access is considered to be beyond the principle of least privilege.
Sure, access rights may be escalated for some persons to accomplish certain tasks such as when replacing another person who has higher privileges, however, the escalated access may have to be selective and temporary.
How the Principle of Least Privilege is Implemented
The Principle of Least Privilege can be implemented in many ways:
- Role-based access control (RBAC): where users are assigned roles and those roles are associated with specific privileges and permissions.
- Access control lists (ACLs): where permissions are assigned to users for specific resources.
- Discretionary access control (DAC): where the owner of a resource decides who can access it.
The Principle of Least Privilege is closely related to the Zero Trust concept, which is an approach to cybersecurity that assumes that all devices and users are untrusted by default and that all access to resources must be verified and authorized.
In summary, the principle of least privilege is a concept in cybersecurity that is closely tied to identity and access management. When access to resources is limited, the risk of unauthorized access, modification, or disclosure is diminished. Principle of Least Privilege can be enforced with access control lists, role-based access control, and discretionary access control.