Comment 7 for bug 184226

I know we are over 3 years on from this suggestion, but I too think that "Install all updates without confirmation" should be added to the software-properties GUI.

As far as I can see, all it has to do is edit:

/etc/apt/apt.conf.d/50unattended-upgrades

and remove the comment in the line:

// "${distro_id} ${distro_codename}-updates";

to enable this facility, as Michael indicated. Indeed, I have made this change manually on my system, and the radio checkbox option "Install security updates without confirmation" is now acting though "Install all updates without confirmation" has been selected, because the GUI seems to be working off the assumption that /etc/apt/apt.conf.d/50unattended-upgrades will never be edited from the default values (which in itself isn't an ideal situation).