The principle of least privilege
Privilege is the authority to perform an action such as accessing a resource or processing some data. The principle of least privilege is the idea that any subject, user, program, process, and so on should only have the minimum required privileges to perform its function. For example, Alice, a regular Linux user, is able to create a file under her own home directory. In other words, Alice at least has the privilege or permission to create a file under her home directory. However, Alice may not be able to create a file under another user's directory because she doesn't have the privilege or permission to do so. If none of Alice's daily tasks actually exercises the privilege to create a file in the home directory, but she does have the privilege to do so, then the administrator for the machine is not complying with the principle of least privilege. In this section, we will first introduce the concept of the authorization model from which...