When Firefox 13 was released almost three weeks ago it touted redesigned Home and New Tab pages to compete with other browsers like Chrome and Opera. However new concerns about these redesigned pages have surfaced. According to The Register, users of Firefox 13 have found that the thumbnails shown on the “New Tab” page can include snapshots of private information. One user discovered that after opening a new tab he found a snapshot of his earlier online banking and webmail sessions complete with account numbers, balances, subject lines etc.
Mozilla has acknowledged that the behavior isn’t desirable and has promised a fix:
We are aware of the concern and have a fix that will be released in a future version of Firefox. Mozilla remains resolute in its commitment to privacy and user control. The new tab thumbnail feature within Firefox does not transmit nor store personal information outside the user’s direct control.
The new tab thumbnails are based on users’ browsing history. All information is contained within the browser and can be deleted at any time. Users can also switch back to using blank new tab screens by clicking the square icon in the top right corner of the browser. That will change the default preference to show a blank page, rather than the most visited websites when a new tab is opened.
Users who share their computer or use Firefox on a public computer should follow best practices for protecting their privacy by utilizing the built-in privacy tools in in Firefox, such as Private Browsing Mode.