Least Privilege and More

“f) Least privilege: Every program and every user of the system should operate using the least set of privileges necessary to complete the job. Primarily, this principle limits the damage that can result from an accident or error. It also reduces the number of potential interactions among privileged programs to the minimum for correct operation, so that unintentional, unwanted, or improper uses of privilege are less likely to occur. Thus, if a question arises related to misuse of a privilege, the number of programs that must be audited is minimized. Put another way, if a mechanism can provide ‘firewalls,’ the principle of least privilege provides a rationale for where to install the firewalls. The military security rule of ‘need-to-know’ is an example of this principle.”