Mozilla is to release an update of its Firefox browser tomorrow that will check for unpatched versions of Adobe's Flash Player commonly user by hackers to carry out attacks.
Users of Firefox 3.0 and 3.5 will be able to install the update to check that the version of Flash Player they are using is up-to-date and secure.
The update is the first in a series planned for Firefox that will target vulnerable browser software from Adobe, Apple, Sun and Microsoft.
Johnathan Nightingale of the Firefox security team said in a blog posting that old versions of plug-ins can cause crashes and other stability problems, and can also be a significant security risk.
"For now, our focus is on the Adobe Flash Player both because of its popularity and because some studies have shown that as many as 80% of users currently have an out-of-date version," he wrote.
Mozilla plans to work with other plug-in suppliers to provide similar checks for their products.
"Keeping your software up to date remains one of the best things you can do to keep yourself safe online," said Nightingale.