Guide to the Secure Configuration of SUSE Linux Enterprise Micro 5

 sudo cvtsudoers -f sudoers /etc/sudoers | grep -E '^Defaults !?(rootpw|targetpw|runaspw)$' 

 Defaults !targetpw
      Defaults !rootpw
      Defaults !runaspw 

 sudo find /etc/sudoers /etc/sudoers.d \( \! -name '*~' -a \! -name '*.*' \) -exec grep -E --with-filename '^[[:blank:]]*Defaults[[:blank:]](.*[[:blank:]])?!?\b(rootpw|targetpw|runaspw)' -- {} \; 

 /etc/sudoers:Defaults !targetpw
      /etc/sudoers:Defaults !rootpw
      /etc/sudoers:Defaults !runaspw 

gpgcheck=1

$ sudo zypper refresh && sudo zypper list-patches -g security

session     required    pam_lastlog.so showfailed

FAIL_DELAY 
        

CREATE_HOME yes

* hard maxlogins 
        

TMOUT=
        

$ sudo chmod o-w FILE
        

$ sudo mkdir /home/USER
        

$ sudo chgrp USER_GROUP /home/USER
        

$ sudo chmod 0740 /home/USER/.INIT_FILE
        

$ sudo chmod 0750 /home/USER
        

ln -sf /dev/null /etc/systemd/system/ctrl-alt-del.target

systemctl mask ctrl-alt-del.target

$ sudo userdel unauthorized_user
        

$ sudo chage -I NUM_DAYS USER
        

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

# grub2-mkpasswd-pbkdf2

set superusers="boot"
password_pbkdf2 boot grub.pbkdf2.sha512.VeryLongString

grubby --update-kernel=ALL

# grub2-mkpasswd-pbkdf2

set superusers="boot"
password_pbkdf2 boot grub.pbkdf2.sha512.VeryLongString

grubby --update-kernel=ALL

$ sudo systemctl enable systemd-journal-upload.service

• 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
        

/bin 
/sbin 
/usr/bin 
/usr/sbin 
/usr/local/bin 
/usr/local/sbin

$ sudo chgrp root DIR
        

/bin 
/sbin 
/usr/bin 
/usr/sbin 
/usr/local/bin 
/usr/local/sbin

$ sudo chown root DIR
        

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

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

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

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

$ sudo systemctl mask --now autofs.service

install usb-storage /bin/false

$ sudo chmod 0640 /var/log/messages

# grep -i messages /etc/permissions.local

/var/log/messages root:root 640

grep "^/usr/sbin/au" /etc/permissions.local

/usr/sbin/audispd root:root 0750
/usr/sbin/auditctl root:root 0750
/usr/sbin/auditd root:root 0750
/usr/sbin/ausearch root:root 0755
/usr/sbin/aureport root:root 0755
/usr/sbin/autrace root:root 0750
/usr/sbin/augenrules root:root 0750

# grep -i audit /etc/permissions.local

/var/log/audit/ root:root 600
/var/log/audit/audit.log root:root 600
/etc/audit/audit.rules root:root 640
/etc/audit/rules.d/audit.rules root:root 640

$ sudo sysctl -w kernel.dmesg_restrict=1

kernel.dmesg_restrict = 1

$ sudo echo "root: " >> /etc/aliases
$ sudo newaliases

$ sudo rm /[path]/[to]/[file]/shosts.equiv

$ sudo find / -name '.shosts' -type f -delete

$ sudo zypper remove telnet-server

ClientAliveInterval 
        

PermitEmptyPasswords no

PermitRootLogin no

IgnoreUserKnownHosts yes

X11Forwarding no

PermitUserEnvironment no

StrictModes yes

Banner /etc/issue

PrintLastLog yes

LogLevel VERBOSE

Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc

Ciphers aes256-ctr,aes192-ctr,aes128-ctr

KexAlgorithms ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256

MACs hmac-sha2-512,hmac-sha2-256

MACs hmac-sha2-512,hmac-sha2-256

-a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b32 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b64 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b32 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b64 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b32 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b64 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b32 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b64 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b32 -S umount2 -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b64 -S umount2 -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b32 -S umount2 -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F arch=b64 -S umount2 -F auid>=1000 -F auid!=unset -F key=perm_mod

-a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/chmod -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/chmod -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/rm -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/rm -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/sbin/semanage -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/sbin/semanage -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/sbin/setfiles -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/sbin/setfiles -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/sbin/setsebool -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/sbin/setsebool -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access

-a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access

-a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access

-a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
-a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access

-a always,exit -F arch=b32 -S rename -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
-a always,exit -F arch=b32 -S rename -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete

-a always,exit -F arch=b64 -S rename -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete
-a always,exit -F arch=b64 -S rename -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete

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

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

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

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

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

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

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

-a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/chfn -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/chfn -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-w /sbin/insmod -p x -k modules

-w /usr/bin/kmod -p x -k modules

-w /usr/bin/kmod -p x -k modules

-w /sbin/modprobe -p x -k modules

-w /sbin/modprobe -p x -k modules

-a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/sbin/pam_timestamp_check
-F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/sbin/pam_timestamp_check
-F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/passwd -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/passwd -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-w /sbin/rmmod -p x -k modules

-a always,exit -F path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset -k privileged-ssh-agent

-a always,exit -F path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset -k privileged-ssh-agent

-a always,exit -F path=/usr/lib/ssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/lib/ssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/su -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/su -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/sudo -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/sudo -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/sudoedit -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/bin/sudoedit -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/sbin/unix_chkpwd -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/sbin/unix_chkpwd -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged

-a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged