A flaw in the way the Firefox and Opera browsers handle an image file could <A HREF="http://www.cio.com/article/184700/Opera_Firefox_Bug_Could_Export_Users_Web_History">allow an attacker to see what Web sites a person has visited.</A>

The problem concerns how the two browsers handle a ".BMP," or bitmap, image file, according to an advisory written by Gynvael Coldwind of Vexillium.org, who posted a video illustrating the problem.