Apple QuickTime Java extensions (QTJava.dll), as used in Safari and other browsers, and when Java is enabled, allows remote attackers to execute arbitrary code via parameters to the toQTPointer method in quicktime.util.QTHandleRef, which can be used to modify arbitrary memory when creating QTPointerRef objects, as demonstrated during the "PWN 2 0WN" contest at CanSecWest 2007.