Researchers discovered a vulnerability in the 802.11n wireless networking standard that could be exploited by a remote attacker to target wireless networks. Researchers from the Expertise Centre for Digital Media at the Hasselt University in Belgium used a technique dubbed Packet-In-Packet (PIP) technique to inject arbitrary frames into wireless networks and interact with services on the internal network. The attack works against almost any Wi-Fi chipset if the victims are connected to an open network and most important is that the attack can be launched without being in proximity of the targeted networks and without requiring a wireless interface card.”]
Source: http://securityaffairs.co/wordpress/38234/hacking/802-11n-flaw.html