The libxul.so!gfxContext::Polygon function in Mozilla Firefox before 28.0, Firefox ESR 24.x before 24.4, Thunderbird before 24.4, and SeaMonkey before 2.25 allows remote attackers to obtain sensitive information from process memory, cause a denial of service (out-of-bounds read and application crash), or possibly bypass the Same Origin Policy via vectors involving MathML polygon rendering.