Mozilla doesn't just want users to have the most current version of Firefox installed, it also is launching a new feature to warn users of outdated and possibly insecure plug-ins. Beginning with an update tomorrow, Firefox 3.5.3 and 3.0.14 will both automatically check which version of Flash users are running and, if needed, prompt them via the "What's New" landing page to visit a link where an updated version is available.

With this Mozilla is hoping to significantly cut the number of users who are currently running old and vulnerable versions of the ubiquitous plug-in. However, it won't stop there -- the company has plans to add checks for other common plug-ins that are often insecure and users fail to upgrade like QuickTime, Reader, Silverlight and Java.

For now the checking will be limited, as it will only occur when a Firefox update is released, but apparently this is only the first step in a multi-step process to make Firefox safer. Starting with Firefox 3.6, for example, the plug-in check functionality should be available through the component currently used to upgrade conventional extensions.