Guide to the Secure Configuration of Alibaba Cloud Linux 2

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

$ sudo yum install gnutls-utils

$ sudo yum install nss-tools

gpgcheck=1

gpgcheck=0

$ sudo grep pam_succeed_if /etc/pam.d/sudo

session     [default=1]    pam_lastlog.so showfailed

$ sudo chage -I NUM_DAYS USER
        

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

FAIL_DELAY 
        

* hard maxlogins 
        

$ sudo mkdir --mode 000 /tmp/tmp-inst

/tmp     /tmp/tmp-inst/            level      root,adm

$ sudo mkdir --mode 000 /var/tmp/tmp-inst

/var/tmp /var/tmp/tmp-inst/    level      root,adm

typeset -xr TMOUT=
        

declare -xr TMOUT=
        

# ls -ld /home/USER
        

# chmod g-w /home/USER
# chmod o-rwx /home/USER
        

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

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

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

$ActionSendStreamDriverAuthMode x509/name

action(type="omfwd" Target="some.example.com" StreamDriverAuthMode="x509/name")

$ActionSendStreamDriverMode 1

action(type="omfwd" ... StreamDriverMode="1")

$DefaultNetstreamDriver gtls

global(DefaultNetstreamDriver="gtls")

$ ls -l LOGFILE
        

$ sudo chgrp root LOGFILE
        

$ ls -l LOGFILE
        

$ sudo chown root LOGFILE
        

$ ls -l LOGFILE
        

$ sudo chmod 640 LOGFILE
        

$ sudo systemctl enable systemd-journald.service

 $ sudo yum install logrotate

# rotate log files frequency
daily

$ sudo yum install syslog-ng-core

$ sudo systemctl enable syslog-ng.service

$ModLoad imtcp
$InputTCPServerRun 514

$ModLoad imudp
$UDPServerRun 514

• 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 yum install libreswan

$ sudo yum install iptables

$ sudo iptables -nL --line-numbers

$ sudo service iptables restart

Chain INPUT (policy ACCEPT)
num  target     prot opt source       destination
1    ACCEPT     all  --  0.0.0.0/0    0.0.0.0/0    state RELATED,ESTABLISHED 
2    ACCEPT     icmp --  0.0.0.0/0    0.0.0.0/0
3    ACCEPT     all  --  0.0.0.0/0    0.0.0.0/0
4    ACCEPT     tcp  --  0.0.0.0/0    0.0.0.0/0    state NEW tcp dpt:22 
5    REJECT     all  --  0.0.0.0/0    0.0.0.0/0    reject-with icmp-host-prohibited 

Chain FORWARD (policy ACCEPT)
num  target     prot opt source       destination
1    REJECT     all  --  0.0.0.0/0    0.0.0.0/0    reject-with icmp-host-prohibited 

Chain OUTPUT (policy ACCEPT)
num  target     prot opt source       destination

$ sudo systemctl enable ufw.service

install dccp /bin/false

install sctp /bin/false

$ sudo chmod +t DIR
        

$ sudo chmod 0600 /boot/System.map*

$ 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 sysctl -w fs.protected_hardlinks=1

fs.protected_hardlinks = 1

$ sudo sysctl -w fs.protected_symlinks=1

fs.protected_symlinks = 1

$ sudo systemctl mask --now autofs.service

kernel /vmlinuz-VERSION ro vga=ext root=/dev/VolGroup00/LogVol00 rhgb quiet nousb

$ sudo sysctl -w kernel.panic_on_oops=1

kernel.panic_on_oops = 1

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

-a always,exit -F arch=b32 -S umount -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 arch=ARCH -S rmdir,unlink,unlinkat,rename,renameat -F auid>=1000 -F auid!=unset -F key=delete

-a always,exit -F arch=ARCH -S rmdir,unlink,unlinkat,rename -S renameat -F auid>=1000 -F auid!=unset -F key=delete

-a always,exit -F arch=ARCH -S rename -F auid>=1000 -F auid!=unset -F key=delete

-a always,exit -F arch=ARCH -S rename -F auid>=1000 -F auid!=unset -F key=delete

-a always,exit -F arch=ARCH -S renameat -F auid>=1000 -F auid!=unset -F key=delete

-a always,exit -F arch=ARCH -S renameat -F auid>=1000 -F auid!=unset -F key=delete

-a always,exit -F arch=ARCH -S rmdir -F auid>=1000 -F auid!=unset -F key=delete

-a always,exit -F arch=ARCH -S rmdir -F auid>=1000 -F auid!=unset -F key=delete

-a always,exit -F arch=ARCH -S unlink -F auid>=1000 -F auid!=unset -F key=delete

-a always,exit -F arch=ARCH -S unlink -F auid>=1000 -F auid!=unset -F key=delete

-a always,exit -F arch=ARCH -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete

-a always,exit -F arch=ARCH -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete

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

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

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

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

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

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

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

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

-a always,exit -F arch=ARCH -S init_module,finit_module,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/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

-w  -p wa -k logins

-w  -p wa -k logins

-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/sbin/init -F auid>=1000 -F auid!=unset -F key=privileged

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

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

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

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

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

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

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

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

$ sudo find PARTITION -xdev -perm /6000 -type f 2>/dev/null

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

-a always,exit -F arch=b32 -S adjtimex -F key=audit_time_rules

-a always,exit -F arch=b64 -S adjtimex -F key=audit_time_rules

-a always,exit -F arch=b32 -S adjtimex -F key=audit_time_rules

-a always,exit -F arch=b64 -S adjtimex -F key=audit_time_rules

-a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules

-a always,exit -F arch=b32 -S clock_settime -F a0=0x0 -F key=time-change

-a always,exit -F arch=b64 -S clock_settime -F a0=0x0 -F key=time-change

-a always,exit -F arch=b32 -S clock_settime -F a0=0x0 -F key=time-change

-a always,exit -F arch=b64 -S clock_settime -F a0=0x0 -F key=time-change

-a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules

-a always,exit -F arch=b32 -S settimeofday -F key=audit_time_rules

-a always,exit -F arch=b64 -S settimeofday -F key=audit_time_rules

-a always,exit -F arch=b32 -S settimeofday -F key=audit_time_rules

-a always,exit -F arch=b64 -S settimeofday -F key=audit_time_rules

-a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules

-a always,exit -F arch=b32 -S stime -F key=audit_time_rules

-a always,exit -F arch=b32 -S stime -F key=audit_time_rules

-a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules

-w /etc/localtime -p wa -k audit_time_rules

-w /etc/localtime -p wa -k audit_time_rules

disable-publishing=yes

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