core-admin/dom0/system-config/qubes.sudoers

%qubes ALL=(ALL) NOPASSWD: ALL

#
# What we're saying above basically means: if the attacker got user access in
# Dom0, then you're screwed already, as there are dozens of ways for the
# attacker to escalate to root from user (e.g. via xend).
#
# Even that is not necessary, in fact! As all the VM control actions can be
# done by user -- after all this is why you can easily start/create VMs and
# apps in VMs from GUI -- all that the attacker needs is user access in Dom0.
#
# So, because in Qubes OS, in Dom0, user account is just as sensitive as root
# account, we don't pretend otherwise, and try to make life a bit easier for
# the user allowing for easy escalation (no need to choose and remember a root
# password in Dom0).
#
# This is also why we don't pretend that Qubes OS is a multiuser system -- it
# is not! (for the reasons given above). The assumption is that there is only
# one user that logs into GUI manager: YOU. This is hardly a limiting factor
# these days, when it's not uncommon for a single person to own not one, but
# several computers, which are not shared with others (phone, tablet, laptops).
# We live in a PC-era! :)
#
# This means that the user password you choose during installation servers only
# one purpose: it allows you to lock your screen while you're away via the
# screen saver. Nothing more!
#
# joanna.
#

Defaults    !requiretty