How to create a list of of only security updates with apt-get?
Install the package apt-show-versions and run
apt-show-versions | grep upgradeable | grep security
to get a listing like this:
firefox:amd64/trusty-security 33.0+build2-0ubuntu0.14.04.1 upgradeable to 34.0+build2-0ubuntu0.14.04.1
firefox-locale-en:amd64/trusty-security 33.0+build2-0ubuntu0.14.04.1 upgradeable to 34.0+build2-0ubuntu0.14.04.1