Crouching tiger - hidden payload
Mario Heiderich, Tilman Frosch, Meiko Jensen, Thorsten Holz · 2011
Scalable Vector Graphics (SVG) images so far played a rather small role on the Internet, mainly due to the lack of proper browser support. Recently, things have changed: the W3C and WHATWG draft specifications for HTML5 require modern web browsers to support SVG images to be embedded in a multitude of ways. Now SVG images can be embedded through the classical method via specific tags such as or , or in novel ways, such as with tags, CSS or inline in any HTML5 document. SVG files are generally considered to be plain images or animations, and security-wise, they are being treated as such (e.g., when an embedment of local or remote SVG images into websites or uploading these files into rich web applications takes place). Unfortunately, this procedure poses great risks for the web applications and the users utilizing them, as it has been proven that SVG files must be considered fully functional, one-file web applications potentially containing HTML, JavaScript, Flash, and other interactive code structures. We found that even more severe problems have resulted from the often improper handling of complex and maliciously prepared SVG files by the browsers.