php: wddx_deserialize null dereference in php_wddx_pop_element

ext/wddx/wddx.c in PHP before 5.6.25 and 7.x before 7.0.10 allows remote attackers to cause a denial of service NULL pointer dereference and application crash or possibly have unspecified other impact via an invalid wddxPacket XML document that is mishandled in a wddxdeserialize call, as...