hi Mike1Firefox, i'll try to answer your questions briefly: # the status vulnerable refers to your currently installed version 17 of the adobe flash plugin. the latest version of flash that you should update to is '''Flash Player 18.0.0.194''' - it fixes various vulnerabilities that are actively exploited in the wild. the update is also available at https://www.adobe.com/products/flashplayer/distribution3.html - for firefox please use the windows exe-installer for plugin-based browsers. # the "author not verified" warning will appear for any unsigned addon at the moment (this will change in firefox 40 for signed addons). addons listed on addons.mozilla.org get created by independent third-party developers most of the time and will subsequently be reviewed by mozilla before they are publicly listed. addons with a green "+ add to firefox" button are fully reviewed and should be safe to use. # less common plugins which data isn't maintained on the plugin check website fall into the unknown plugins category. since most of the time they will be unnecessary for normal browsing and aren't used to display web content, you could go ahead and set them to '''never activate''' in the firefox menu ≡ > plugins > extensions.