Sample Security Profile for OpenEmbedded Distros

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

gpgcheck=1

$ sudo chgrp root /etc/issue

$ sudo chgrp root /etc/motd

$ sudo chown root /etc/issue 

$ sudo chown root /etc/motd 

$ sudo chmod 0644 /etc/issue

$ sudo chmod 0644 /etc/motd

$ sudo chage -I NUM_DAYS USER

$ sudo chage -M 180 -m 7 -W 7 USER

typeset -xr TMOUT=

declare -xr TMOUT=

$ sudo chgrp USER_GROUP /home/USER

$ sudo chown USER /home/USER

# echo $PATH

$ sudo chgrp root /boot/grub2/grub.cfg

$ sudo chown root /boot/grub2/grub.cfg 

$ sudo chmod 600 /boot/grub2/grub.cfg

# grub2-setpassword

• 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 dnf install iptables

$ sudo chmod +t DIR

$ findmnt -n -l -k -it $(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,)

$ sudo find MOUNTPOINT -xdev -nogroup 2>/dev/null

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

$ sudo chgrp root /etc/at.allow

$ sudo chgrp root /etc/cron.allow

$ sudo chown root /etc/at.allow 

$ sudo chown root /etc/cron.allow 

$ sudo chmod 0640 /etc/at.allow

$ sudo chmod 0640 /etc/cron.allow

$ sudo systemctl mask --now dhcpd.service

$ sudo systemctl mask --now named.service

$ sudo systemctl mask --now vsftpd.service

$ sudo systemctl mask --now httpd.service

$ sudo systemctl mask --now dovecot.service

$ sudo systemctl mask --now ypserv.service

$ sudo rm /etc/hosts.equiv

$ rm ~/.rhosts

$ sudo systemctl mask --now squid.service

$ sudo systemctl mask --now smb.service

$ sudo systemctl mask --now snmpd.service

ClientAliveInterval 

HostbasedAuthentication no

Protocol 2

PermitEmptyPasswords no

IgnoreRhosts yes

PermitRootLogin no

PermitUserEnvironment no

UsePAM yes

Banner /etc/issue

LogLevel INFO

LogLevel VERBOSE

MaxAuthTries 

MaxSessions 

MaxStartups