# Principle of least privilege

> The principle of least privilege gives each person and system only the access needed to do the job, and nothing more, for no longer than needed.

The principle of least privilege says that every user, and every program acting for a user, should have only the access needed to do their job. NIST describes it as restricting access privileges to the minimum necessary to accomplish assigned tasks.

In practice it applies to admin rights on laptops, roles in business software, shared drives, the bank portal and the accounting system.

### Why it matters

Every unnecessary permission is a risk: a mistake that deletes data, a stolen password that opens more systems than it should, or a person able to both create and approve a payment. Least privilege limits how much damage any single account can do.

### How to apply it

- Grant access by role, with a short list of standard roles per system.
- Give admin rights to as few people as possible, through separate accounts used only for admin work.
- Make elevated or temporary access expire.
- Review access when people change roles, not only when they leave.

### Example

A new accounts payable clerk needs to enter bills in the accounting system (illustrative). She does not need to approve payments or edit supplier bank details, and admin rights to the bank portal stay with the controller.

### Common pitfalls

- **"Same access as Jane"**, which copies years of accumulated permissions to a new hire.
- **Everyone is an admin** because it saves support tickets.
- **Temporary access that becomes permanent.**
- **Privilege creep**: people move teams and keep the old access on top of the new.
- **Shared accounts**, which make access impossible to limit or trace.

Sources:

- [NIST Computer Security Resource Center, Glossary: least privilege](https://csrc.nist.gov/glossary/term/least_privilege)

Page: https://easy.wf/glossary/least-privilege