Single User mode is password protected by the root password on RHEL 7

# RHEL 5
# ——————————————————————————————

# To force users to enter password in Single User mode, add following line to /etc/inittab:

~:S:respawn:/sbin/sulogin

# The changes to this file takes effect after a system reboot

# To make init re-read the /etc/inittab without rebooting the system, type the command

/sbin/init q

# RHEL 6
# ——————————————————————————————

# Edit /etc/inittab and add “su:S:wait:/sbin/sulogin” before ‘initdefault’ line:

vi /etc/inittab
[…]
su:S:wait:/sbin/sulogin
id:3:initdefault:

# Edit /etc/sysconfig/init and replace “SINGLE=/sbin/sushell” with “SINGLE=/sbin/sulogin”:

vi /etc/sysconfig/init
[…]
# Set to ‘/sbin/sulogin’ to prompt for password on single-user mode
# Set to ‘/sbin/sushell’ otherwise
SINGLE=/sbin/sulogin

# RHEL 7
# ——————————————————————————————

# By default, Single User mode is password protected by the root password on RHEL 7:

cat /usr/lib/systemd/system/rescue.service
[…]

[Service]
Environment=HOME=/root
WorkingDirectory=/root
ExecStartPre=-/bin/plymouth quit
ExecStartPre=-/bin/echo -e ‘Welcome to emergency mode! After logging in, type […]
ExecStart=-/bin/sh -c “/usr/sbin/sulogin; /usr/bin/systemctl –fail –no-block default” <--- Type=idle StandardInput=tty-force StandardOutput=inherit StandardError=inherit KillMode=process IgnoreSIGPIPE=no SendSIGHUP=yes