Mozilla unblocks Microsoft plug-in

Decides add-on software isn't malicious after all.

Mozilla has decided to unblock a Microsoft plug-in for Firefox, after finally deciding that it poses no security threat.

The Firefox developer had originally blocked the plug-in that had been quietly pushed out by Microsoft, saying that it presented a security risk.

The add-on was released as part of a .Net software update in February. It could be disabled but was tricky to completely remove.

Microsoft warned that Firefox users who have not applied a recent Internet Explorer patch are vulnerable to a "browse-and-get-owned attack" because of the add-on.

The company said that users would be safe if they had installed the update for Internet Explorer.

Mozilla responded by automatically blocking two add-ons, the Microsoft .Net Framework Assistant and a related plug-in called the Windows Presentation Foundation.

However, when we woke up this morning the so-called security threat was nothing of the sort.

Mozilla apparently has had a rethink and decided that the 'security threat' is really nothing to worry about after all, and has unblocked it.

Mike Shaver, Mozilla's vice president of engineering, had claimed in his blog that Microsoft agreed to this plan, but he is now saying that he changed his mind after Microsoft told him that the Framework Assistant was not "a mechanism for exploiting the vulnerabilities".