Administrative access rights

The operating system provides privileged access rights for system administration.

System privilege is based on user and group IDs. Users with effective user or group IDs of 0 are recognized as privileged.

Processes with effective user IDs of 0 are known as root-user processes and can:

• Read or write any object
• Call any system function
• Perform certain subsystem control operations by executing setuid-root programs.

You can manage the system using two types of privilege: the su command privilege and setuid-root program privilege. The su command allows all programs you invoke to function as root-user processes. The su command is a flexible way to manage the system, but it is not very secure.

Making a program into a setuid-root program means the program is a root-user-owned program with the setuid bit set. A setuid-root program provides administrative functions that ordinary users can perform without compromising security; the privilege is encapsulated in the program rather than granted directly to the user. It can be difficult to encapsulate all necessary administrative functions in setuid-root programs, but it provides more security to system managers.