CIS Amazon Linux 2023 Benchmark for Level 1 - Server

$ sudo update-crypto-policies --set 
         

authselect enable-feature with-pwhistory

authselect enable-feature with-pwhistory

password    requisite     pam_pwquality.so try_first_pass local_users_only retry=3 authtok_type=

difok = 4
minlen = 14
dcredit = -1
ucredit = -1
lcredit = -1
ocredit = -1
maxrepeat = 3

ENCRYPT_METHOD 
         

password    sufficient    pam_unix.so 
          other arguments...
         

password    sufficient    pam_unix.so 
          other arguments...
         

INACTIVE=
         

$ sudo getent passwd | awk -F: '{ print $1}' | uniq -d

PASS_MAX_DAYS 
         

PASS_MIN_DAYS 
         

$ sudo chage -M 
          USER
         

$ sudo chage -m 1 USER
         

$ sudo chage --warndays 
          USER
         

PASS_WARN_AGE 
         

$ sudo chage --inactive 30USER
         

$ sudo awk -F: '!$2 {print $1}' /etc/shadow

$ sudo passwd [username]

$ sudo passwd -l [username]

$ sudo usermod -L account
         

$ sudo usermod -s /sbin/nologin account
         

auth required pam_wheel.so use_uid group=
         

# ls -ld DIR
         

PATH=:/bin
PATH=/bin:
PATH=/bin::/sbin

umask 
         

UMASK 
         

umask 
         

$ sudo sysctl -w net.ipv6.conf.all.accept_ra=0

net.ipv6.conf.all.accept_ra = 0

$ sudo sysctl -w net.ipv6.conf.all.accept_redirects=0

net.ipv6.conf.all.accept_redirects = 0

$ sudo sysctl -w net.ipv6.conf.all.accept_source_route=0

net.ipv6.conf.all.accept_source_route = 0

$ sudo sysctl -w net.ipv6.conf.all.forwarding=0

net.ipv6.conf.all.forwarding = 0

$ sudo sysctl -w net.ipv6.conf.default.accept_ra=0

net.ipv6.conf.default.accept_ra = 0

$ sudo sysctl -w net.ipv6.conf.default.accept_redirects=0

net.ipv6.conf.default.accept_redirects = 0

$ sudo sysctl -w net.ipv6.conf.default.accept_source_route=0

net.ipv6.conf.default.accept_source_route = 0

$ sudo sysctl -w net.ipv4.conf.all.accept_redirects=0

net.ipv4.conf.all.accept_redirects = 0

$ sudo sysctl -w net.ipv4.conf.all.accept_source_route=0

net.ipv4.conf.all.accept_source_route = 0

$ sudo sysctl -w net.ipv4.conf.all.log_martians=1

net.ipv4.conf.all.log_martians = 1

$ sudo sysctl -w net.ipv4.conf.all.rp_filter=1

net.ipv4.conf.all.rp_filter = 1

$ sudo sysctl -w net.ipv4.conf.all.secure_redirects=0

net.ipv4.conf.all.secure_redirects = 0

$ sudo sysctl -w net.ipv4.conf.default.accept_redirects=0

net.ipv4.conf.default.accept_redirects = 0

$ sudo sysctl -w net.ipv4.conf.default.accept_source_route=0

net.ipv4.conf.default.accept_source_route = 0

$ sudo sysctl -w net.ipv4.conf.default.log_martians=1

net.ipv4.conf.default.log_martians = 1

$ sudo sysctl -w net.ipv4.conf.default.rp_filter=1

net.ipv4.conf.default.rp_filter = 1

$ sudo sysctl -w net.ipv4.conf.default.secure_redirects=0

net.ipv4.conf.default.secure_redirects = 0

$ sudo sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1

net.ipv4.icmp_echo_ignore_broadcasts = 1

$ sudo sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1

net.ipv4.icmp_ignore_bogus_error_responses = 1

$ sudo sysctl -w net.ipv4.tcp_syncookies=1

net.ipv4.tcp_syncookies = 1

$ sudo sysctl -w net.ipv4.conf.all.send_redirects=0

net.ipv4.conf.all.send_redirects = 0

$ sudo sysctl -w net.ipv4.conf.default.send_redirects=0

net.ipv4.conf.default.send_redirects = 0

$ sudo sysctl -w net.ipv4.ip_forward=0

net.ipv4.ip_forward = 0

$ sudo chgrp root /etc/group-

$ sudo chgrp root /etc/gshadow-

$ sudo chgrp root /etc/passwd-

$ sudo chgrp root /etc/shadow-

$ sudo chgrp root /etc/group

$ sudo chgrp root /etc/gshadow

$ sudo chgrp root /etc/passwd

$ sudo chgrp root /etc/shadow

$ sudo chown root /etc/group- 

$ sudo chown root /etc/gshadow- 

$ sudo chown root /etc/passwd- 

$ sudo chown root /etc/shadow- 

$ sudo chown root /etc/group 

$ sudo chown root /etc/gshadow 

$ sudo chown root /etc/passwd 

$ sudo chown root /etc/shadow 

$ sudo chmod 0644 /etc/group-

$ sudo chmod 0000 /etc/gshadow-

$ sudo chmod 0644 /etc/passwd-

$ sudo chmod 0000 /etc/shadow-

$ sudo chmod 0644 /etc/group

$ sudo chmod 0000 /etc/gshadow

$ sudo chmod 0644 /etc/passwd

$ sudo chmod 0000 /etc/shadow

$ sudo sysctl -w kernel.randomize_va_space=2

kernel.randomize_va_space = 2

$ sudo systemctl mask --now rpcbind.service

$ sudo systemctl mask --now nfs-server.service