I wrote about manual installation of Adobe Flash Player earlier but if you don’t want to update it manually, you can add it to sources list so it can be updated automatically.
It will work on almost every browser on your Debian system.
Lets start with the installation.
Open a terminal and edit the file /etc/apt/sources.list
sudo nano /etc/apt/sources.list
Make sure you have contrib non-free after main.
If not, you can add this line:
deb ftp://ftp.debian.org/debian stable main contrib non-free
Save and exit the file.
Type the following command to update packages:
sudo apt-get update
To install Adobe Flash Player, you need to type the following:
sudo apt-get install flashplugin-nonfree
If all worked fine, you should see Adobe Flash Player plugin in your web browser.
In Firefox/Iceweasel go to Menu > Add-ons > Plugins