A vulnerability in the handling of 802.11w Protected Management Frames (PAF) by Cisco Aironet 3800 Series Access Points could allow an unauthenticated, adjacent attacker to terminate a valid user connection to an affected device, aka Denial of Service. The vulnerability exists because the affected device does not properly validate 802.11w PAF disassociation and deauthentication frames that it receives. An attacker could exploit this vulnerability by sending a spoofed 802.11w PAF frame from a valid, authenticated client on an adjacent network to an affected device. A successful exploit could allow the attacker to terminate a single valid user connection to the affected device. This vulnerability affects Access Points that are configured to run in FlexConnect mode. Cisco Bug IDs: CSCvc20627.