Most workstation operating systems support passwords, provide an insulating and protective layer of software between the user program and the hardware, and provide memory isolation between user program processes and the operating system. However, there are other weaknesses that usually are not addressed.
Any application can potentially monopolize all the resources of a system.
That is, although a user may expect an application to affect only the files the user specified, a program can actually manipulate any resource the user can manipulate. Tty's and pseudo-tty's are not handled in a secure manner. A program can open a terminal and wait for another program to open the same terminal. Programs share the same directories to create temporary files, which means a program can modify or delete the work files of other programs. Programs are built with shared libraries containing references to relative rather than absolute pathnames.