1.4.3 Ensure authentication required for single user mode (Scored)

Level 1 - Server 
Level 1 - Workstation

Single user mode is used for recovery when the system detects an issue during boot or by manual selection from the bootloader.

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

Perform the following to determine if a password is set for the root user:

# grep ^root:[*\!]: /etc/shadow

No results should be returned.

Run the following command and follow the prompts to set a password for the root user:

# passwd root