upgrade-ssh-ubuntu-18.04.sh

sudo apt update
sudo apt install build-essential zlib1g-dev libssl-dev -y 
sudo mkdir /var/lib/sshd
sudo chmod -R 700 /var/lib/sshd/
sudo chown -R root:sys /var/lib/sshd/
wget -c https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-8.4p1.tar.gz
tar -xzf openssh-8.4p1.tar.gz
cd openssh-8.4p1/
sudo apt install libpam0g-dev libselinux1-dev -y 
sudo apt install libkrb5-dev -y
./configure --with-kerberos5 --with-md5-passwords --with-pam --with-selinux --with-privsep-path=/var/lib/sshd/ --sysconfdir=/etc/ssh
make
sudo make install