How do I install Adobe Flash on Debian Wheezy?

aptitude install flashplugin-nonfree
if fail

Check your settings in /etc/apt/sources.list.

If this is a fresh install, most likely you don't have the contrib and non-free portions enabled yet. Look for the line that says

deb http://ftp.XX.debian.org/debian/ wheezy main

and change it to

deb http://ftp.XX.debian.org/debian/ wheezy main contrib non-free

then run apt-get update and try again. It should be there as flashplugin-nonfree.

Adobe's Flash plugin, while freely downloadable, doesn't meet the Debian Free Software Guidelines (DFSG) which define "free" as "open source", so debian has created a downloader package in the contrib section which can then download and install the flash player.