Mozilla Firefox 1.5.0.4, 2.0.x before 2.0.0.8, Mozilla Suite 1.7.13, Mozilla SeaMonkey 1.0.2 and other versions before 1.1.5, and Netscape 8.1 and earlier allow user-assisted remote attackers to read arbitrary files by tricking a user into typing the characters of the target filename in a text box and using the OnKeyDown, OnKeyPress, and OnKeyUp Javascript keystroke events to change the focus and cause those characters to be inserted into a file upload input control, which can then upload the file when the user submits the form.
Mozilla Suite 1.7.13, Mozilla Firefox 1.5.0.3 and possibly other versions before before 1.8.0, and Netscape 7.2 and 8.1, and possibly other versions and products, allows remote user-assisted attackers to obtain information such as the installation path by causing exceptions to be thrown and checking the message contents.