Exposure of Sensitive Information to an Unauthorized Actor
Mozilla Firefox 4.x through 9.0, Thunderbird 5.0 through 9.0, and SeaMonkey before 2.7 do not properly initialize data for image/vnd.microsoft.icon images, which allows remote attackers to obtain potentially sensitive information by reading a PNG image that was created through conversion from an ICO image.
CWE-200 - Information Exposure
An information exposure vulnerability is categorized as an information flow (IF) weakness, which can potentially allow unauthorized access to otherwise classified information in the application, such as confidential personal information (demographics, financials, health records, etc.), business secrets, and the application's internal environment.