<P> Users who have been delegated extra levels of control are called privileged . Users who lack most privileges are defined as unprivileged, regular, or normal users . </P> <P> Privileges can either be automatic, granted, or applied for . </P> <P> An automatic privilege exists when there is no requirement to have permission to perform an action . For example, on systems where people are required to log into a system to use it, logging out will not require a privilege . Systems that do not implement file protection - such as MS - DOS - essentially give unlimited privilege to perform any action on a file . </P> <P> A granted privilege exists as a result of presenting some credential to the privilege granting authority . This is usually accomplished by logging on to a system with a username and password, and if the username and password supplied are correct, the user is granted additional privileges . </P>

Give practical examples of what can happen if there is an os flaw in granting privileges