Information
Single user mode (rescue mode) is used for recovery when the system detects an issue during boot or by manual selection from the bootloader.
Note: The systemctl option --fail is synonymous with --job-mode=fail. Using either is acceptable.
Rationale:
Requiring authentication in single user mode (rescue mode) prevents an unauthorized user from rebooting the system into single user to gain root privileges without credentials.
Solution
Edit /usr/lib/systemd/system/rescue.service and /usr/lib/systemd/system/emergency.service and set ExecStart to use /sbin/sulogin or /usr/sbin/sulogin:
ExecStart=-/bin/sh -c '/sbin/sulogin; /usr/bin/systemctl --fail --no-block default'
Item Details
Category: CONFIGURATION MANAGEMENT, SYSTEM AND SERVICES ACQUISITION
References: 800-53|CM-1, 800-53|CM-2, 800-53|CM-6, 800-53|CM-7, 800-53|CM-7(1), 800-53|CM-9, 800-53|SA-3, 800-53|SA-8, 800-53|SA-10, CSCv7|5.1, Rule-ID|SV-204437r603261_rule
Control ID: ba2f678ec5c10f0b96d24c1004225e32418c937a9ebacf84a35424c314f7dc37