Firefox 0.9, Thunderbird 0.6 and other versions before 0.9, and Mozilla 1.7 before 1.7.5 save temporary files with world-readable permissions, which allows local users to read certain web content or attachments that belong to other users, e.g. content that is managed by helper applications such as PDF.

Mozilla before 1.7, Firefox before 0.9, and Thunderbird before 0.7 allows remote attackers to determine the location of files on a user's hard drive by obscuring a file upload control and tricking the user into dragging text into that control.