The VertexBufferInterface::reserveVertexSpace function in libGLES in ANGLE, as used in Mozilla Firefox before 41.0 and Firefox ESR 38.x before 38.3 on Windows, incorrectly allocates memory for shader attribute arrays, which allows remote attackers to execute arbitrary code or cause a denial of service (buffer overflow and application crash) via crafted (1) OpenGL or (2) WebGL content.