The Adobe Flash Player plugin is use for viewing multimedia, and streaming video and audio, on a Firefox web browser. The same plugin is used by Google chrome and other browsers. Keeping your third-party plugins such as flash player up to date helps Firefox run safely and smoothly.
As explained earlier you need to install the flashplugin-nonfree package under Debian and Ubuntu Linux to get flash support for Firefox and other browsers. You can check plugins status by visiting the following url:
How Do I Update the Adobe Flash Player Under Debian or Ubuntu Linux?
Open a terminal window (select Applications > Accessories > Terminal). Switch to the root user by typing su - and entering the root password, when prompted:
$ su -
# update-flashplugin-nonfree --install
$ sudo /sbin/update-flashplugin-nonfree --install
The update-flashplugin-nonfree command takes care of downloading, removing the installed Adobe Flash Plugin if it has been reported as insecure, or, if a newer suitable version is available, downloading a newer Adobe Flash Player and its installer from the Adobe download site. From the man page:
--install To install, update or remove the Adobe Flash Player depending on downloaded last minute information from Debian about suitable versions. --uninstall To remove the Adobe Flash Player.
Next, restart the Firefox and all other browsers. Again, check plugins status by visiting the following url: