Date: 2023apr27 Q. sshd: hide version in banner A. When you do:

echo | nc localhost 22 SSH-2.0-OpenSSH_7.0

The sshd program is shown along with its version. In file /etc/ssh/sshd_config setting

VersionAddendum none Banner none

doesn't change anything. I read that the general format is:

SSH-<version>-<comment>

So it would be fun to throw in a confusing comment. But looking at the actual code for OpenSSH https://github.com/openssh/openssh-portable/blob/71508e06fab14bc415a79a08f5535ad7bffa93d9/sshd.c#L367 We can see its not possible, sorry. Somebody did it by patching the binary, but what about updates?