Page 1127 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

that all users have a well-defined job description that personnel
understand. Without a specific job description, it is not possible to

know what privileges users need.

This principle extends beyond just accessing data, though. It also

applies to system access. For example, in many networks regular users
can log on to any computer in the network using a network account.
However, organizations commonly restrict this privilege by preventing
regular users from logging on to servers or restricting a user to logging
on to a single workstation.

One way that organizations violate this principle is by adding all users
to the local Administrators group or granting root access to a

computer. This gives the users full control over the computer.
However, regular users rarely need this much access. When they have
this much access, they can accidentally (or intentionally) cause
damage within the system such as accessing or deleting valuable data.

Additionally, if a user logs on with full administrative privileges and
inadvertently installs malware, the malware can assume full
administrative privileges of the user’s account. In contrast, if the user

logs on with a regular user account, malware can only assume the
limited privileges of the regular account.

Least privilege is typically focused on ensuring that user privileges are
restricted, but it also applies to other subjects, such as applications or
processes. For example, services and applications often run under the
context of an account specifically created for the service or application.
Historically, administrators often gave these service accounts full

administrative privileges without considering the principle of least
privilege. If attackers compromise the application, they can potentially
assume the privileges of the service account, granting the attacker full
administrative privileges.

Additional concepts personnel should consider when implementing
need-to-know and least privilege are entitlement, aggregation, and

transitive trusts.

Entitlement Entitlement refers to the amount of privileges granted
to users, typically when first provisioning an account. In other words,