Based on the automatic updates article, the following configuration template, in conjunction with the unattended-upgrades package is meant to periodically update Debian to the recent stable distribution.

• Install the unattended-upgrades package with:

aptitude install unattended-upgrades

• Change directory to /etc/apt and issue as root:

svn export http://svn.grimore.org/configuration-templates/debian/apt/unattended-upgrades . --force

Issue:

unattended-upgrades --dry-run --debug

to check that the unattended upgrades are working.