Mozilla will warn users if their version of the popular Adobe Flash Player plug-in is out of date. Once the browser is updated, Mozilla will present the user with a visual notice on its first-run Web site that the Flash Player plugin contains security and stability vulnerabilities. Mozilla Human Shield Johnathan Nightingale said Mozilla will work with other plugin vendors to provide similar checks for their products in the future. Some studies have shown that as many as 80% of users currently have an out-of-date version.
Source: https://threatpost.com/firefox-check-adobe-flash-patch-090809/72233/