It's just about possible for someone to accidentally do something like this, on "host": # docker run -it -p 2222:22/tcp alpine / # apk add openssh-server

It's just about possible for someone to accidentally do something like this, on "host": # docker run -it -p 2222:22/tcp alpine / # apk add openssh-server / # for t in ecdsa ed25519 rsa ; do ssh-keygen -t $t -C root -P '' -f /etc/ssh/ssh_host_${t}_key ; done / # echo PermitRootLogin yes >> /etc/ssh/sshd_config / # echo PermitEmptyPasswords yes >> /etc/ssh/sshd_config / # /usr/sbin/sshd Then, on another machine: ssh -p 2222 root@host