- login as root (superuser)
- edit your /etc/apt/sources.list and add
# Debian 7 (flash player adobe)
deb http://ftp.de.debian.org/debian wheezy main contrib - install "flashplugin-nonfree"
# apt-get install flashplugin-nonfree
- your apt will ask you to install dependency packages, answer it with "y"
- after "flashpluin-nonfree" installed, it will download a proper flash player (latest) that suit your operating system