A new bug discovered in the Firefox web browser could allow attackers to gain access to files stored on a computer through malicious code injected into the browser’s built-in PDF viewer. Researchers first discovered attackers exploiting the weak spot in Firefox through a malicious advertisement on a news site in Russia that searched for sensitive user files and uploaded them to a remote server
As news of the vulnerability in Firefox spreads, it is likely that other attackers will now try to take advantage of it before users download a patch. Luckily, Mozilla has already released a patch and Firefox users are advised to update to the latest version of Firefox (39.0.3) immediately.
Here’s how to do a manual update for Firefox:
1.On the menu bar click the Firefox menu and select About Firefox.
2.The About Firefox window will open and Firefox will begin checking for updates and downloading them automatically.
3.When the updates are ready to be installed, click Restart Firefox to Update.