Australian Cyber Security Centre (ACSC) Essential Eight

• GnuTLS library
• OpenSSL library
• NSS library
• OpenJDK
• Libkrb5
• BIND
• OpenSSH

$ sudo yum install rear

gpgcheck=1

gpgcheck=0

$ sudo subscription-manager register

$ sudo rpm --import /media/cdrom/RPM-GPG-KEY

sudo rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

$ sudo yum update

-a always,exit -F arch=ARCH -S sethostname,setdomainname -F key=audit_rules_networkconfig_modification
-w /etc/issue -p wa -k audit_rules_networkconfig_modification
-w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
-w /etc/hosts -p wa -k audit_rules_networkconfig_modification
-w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification

-a always,exit -F arch=ARCH -S sethostname,setdomainname -F key=audit_rules_networkconfig_modification
-w /etc/issue -p wa -k audit_rules_networkconfig_modification
-w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
-w /etc/hosts -p wa -k audit_rules_networkconfig_modification
-w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification

-w /etc/sudoers -p wa -k actions
-w /etc/sudoers.d/ -p wa -k actions

-w /etc/sudoers -p wa -k actions
-w /etc/sudoers.d/ -p wa -k actions

-w /etc/group -p wa -k audit_rules_usergroup_modification
-w /etc/passwd -p wa -k audit_rules_usergroup_modification
-w /etc/gshadow -p wa -k audit_rules_usergroup_modification
-w /etc/shadow -p wa -k audit_rules_usergroup_modification
-w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification

-w /etc/group -p wa -k audit_rules_usergroup_modification
-w /etc/passwd -p wa -k audit_rules_usergroup_modification
-w /etc/gshadow -p wa -k audit_rules_usergroup_modification
-w /etc/shadow -p wa -k audit_rules_usergroup_modification
-w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification

-a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
    -a always,exit -F arch=b32 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
    -a always,exit -F arch=b32 -S setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b64 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
    -a always,exit -F arch=b64 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
    -a always,exit -F arch=b64 -S setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=ARCH -S init_module,delete_module -F key=modules

-w /var/log/tallylog -p wa -k logins
-w  -p wa -k logins
-w /var/log/lastlog -p wa -k logins

-w /var/log/tallylog -p wa -k logins
-w  -p wa -k logins
-w /var/log/lastlog -p wa -k logins

flush = 

• drop
  

  Any incoming network packets are dropped, there is no reply. Only outgoing network connections are possible.

• block
  

  Any incoming network connections are rejected with an icmp-host-prohibited message for IPv4 and icmp6-adm-prohibited for IPv6. Only network connections initiated from within the system are possible.

• public
  

  For use in public areas. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted.

• external
  

  For use on external networks with masquerading enabled especially for routers. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted.

• dmz
  

  For computers in your demilitarized zone that are publicly-accessible with limited access to your internal network. Only selected incoming connections are accepted.

• work
  

  For use in work areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.

• home
  

  For use in home areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.

• internal
  

  For use on internal networks. You mostly trust the other computers on the networks to not harm your computer. Only selected incoming connections are accepted.

• trusted
  

  All network connections are accepted.

# firewall-cmd --zone=public --list-all

# firewall-cmd --zone=public --list-all
public
  interfaces:
  services: mdns dhcpv6-client ssh
  ports:
  forward-ports:
  icmp-blocks: source-quench

# firewall-cmd --get-service

# firewall-cmd --get-service
amanda-client bacula bacula-client dhcp dhcpv6 dhcpv6-client dns ftp
high-availability http https imaps ipp ipp-client ipsec kerberos kpasswd
ldap ldaps libvirt libvirt-tls mdns mountd ms-wbt mysql nfs ntp openvpn
pmcd pmproxy pmwebapi pmwebapis pop3s postgresql proxy-dhcp radius rpc-bind
samba samba-client smtp ssh telnet tftp tftp-client transmission-client
vnc-server wbem-https

# firewall-cmd --get-service --permanent

$ sudo chmod +t DIR

$ sudo sysctl -w kernel.dmesg_restrict=1

kernel.dmesg_restrict = 1

$ sudo sysctl -w kernel.kexec_load_disabled=1

kernel.kexec_load_disabled = 1

$ sudo sysctl -w kernel.unprivileged_bpf_disabled=1

kernel.unprivileged_bpf_disabled = 1

$ sudo sysctl -w kernel.yama.ptrace_scope=1

kernel.yama.ptrace_scope = 1

$ sudo sysctl -w net.core.bpf_jit_harden=2

net.core.bpf_jit_harden = 2

$ sudo systemctl mask --now avahi-daemon.service

$ sudo yum erase xinetd

$ sudo systemctl mask --now xinetd.service

$ sudo yum erase rsh-server

 $ sudo yum erase talk-server

$ sudo yum erase talk

$ sudo yum erase telnet-server

$ sudo systemctl mask --now telnet.socket

 $ sudo yum erase squid

$ sudo systemctl mask --now squid.service

 $ sudo yum erase quagga

$ sudo systemctl mask --now zebra.service

PermitEmptyPasswords no

GSSAPIAuthentication no

IgnoreRhosts yes

PermitRootLogin no

IgnoreUserKnownHosts yes

PermitUserEnvironment no

StrictModes yes

PrintLastLog yes

LogLevel INFO