Why fresh Virtualmin does allow to browse files for all users from the beginning?

That’s the thing I’m trying to express: chroot jails for ssh users is not a security feature. You don’t have a more secure system with ssh jails enabled. Some people prefer it, but it is not more secure.

Oh, and there is no option for it during install, but I think you can do the following to turn it on immediately after install:

# sed -i 's/defujail=0/defujail=1/' /etc/webmin/virtual-server/config

And, restarting Webmin.

Oh, actually it looks like there’s a virtualmin command for it, too.

# virtualmin modify-template --id 0 --setting ujail --value 1

That’s probably the better choice. (Note --id is the template ID, and 0 is for the default template…if you have more templates, you’d want to alter those, too.)