Security & Privacy

The Mozilla Foundation has issued updates to its Firefox web browser and Thunderbird e-mail client, with critical vulnerabilities fixed in both of them. In addition, there are now three concurrent versions of Firefox.

The just-released Firefox 5 sees fixes for eight flaws, five of which are critical. And Firefox 3.6 sees a half-dozen fixes, five of which are critical. In addition, Firefox 5 features Mozilla’s Do Not Track privacy system.

Also, as Gregg Keizer points out at Computerworld, Mozilla has ended security update support for Firefox 4. Users who need to stay with version 4 for any reason – incompatibility, or simply a business environment that has not yet approved Firefox 5 – will be left with an insecure browser.

Thunderbird 3.1 was also updated with two security fixes, one of which is critical.

Users can update their software using the program’s built-in updaters, or can download new versions from the Mozilla website.