Details

Since /etc/init determines what run state the system is in, setting the entry in /etc/inittab will force single user authentication.

Rationale:

Requiring authentication in single user mode prevents an unauthorized user from rebooting the system into single user to gain root privileges without credentials.

Solution

Add the following to /etc/inittab:

~:S:wait:/sbin/sulogin

Default Value:

OS Default: No

Supportive Information

The following resource is also helpful.

• https://workbench.cisecurity.org/files/3096

This security hardening control applies to the following category of controls within NIST 800-53: Configuration Management.This control applies to the following type of system Unix.

References

• 800-53|CM-6
• CSCv7|5.1

Source

• Tenable.com/audits