WebKit, as used in Apple Safari before 6.1.4 and 7.x before 7.0.4, does not properly interpret Unicode encoding, which allows remote attackers to spoof a postMessage origin, and bypass intended restrictions on sending a message to a connected frame or window, via crafted characters in a URL.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.