A vulnerability when handling incoming 802.11 Association Requests for Cisco Aironet 1800 Series Access Point (APs) on Qualcomm Atheros (QCA) based hardware platforms could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected system. A successful exploit could prevent new clients from joining the AP. The vulnerability is due to incorrect handling of malformed or invalid 802.11 Association Requests. An attacker could exploit this vulnerability by sending a malformed stream of 802.11 Association Requests to the local interface of the targeted device. A successful exploit could allow the attacker to cause a DoS situation on an affected system, causing new client 802.11 Association Requests to fail. This vulnerability affects the following Cisco products: Aironet 1560 Series Access Points, Aironet 1810 Series OfficeExtend Access Points, Aironet 1810w Series Access Points, Aironet 1815 Series Access Points, Aironet 1830 Series Access Points, Aironet 1850 Series Access Points, Aironet 2800 Series Access Points, Aironet 3800 Series Access Points. Cisco Bug IDs: CSCvg02116.