WebKit, as used in Apple Safari before 4.1.3 and 5.0.x before 5.0.3, Google Chrome before 6.0.472.53, and webkitgtk before 1.2.6, does not properly restrict read access to images derived from CANVAS elements, which allows remote attackers to bypass the Same Origin Policy and obtain potentially sensitive image data via a crafted web site.
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.