A vulnerability in the access point (AP) joining process of the Control and Provisioning of Wireless Access Points (CAPWAP) protocol of Cisco IOS XE Software for Wireless LAN Controllers (WLCs) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to a logic error that occurs when certain conditions are met during the AP joining process. An attacker could exploit this vulnerability by adding an AP that is under their control to the network. The attacker then must ensure that the AP successfully joins an affected wireless controller under certain conditions. Additionally, the attacker would need the ability to restart a valid AP that was previously connected to the controller. A successful exploit could allow the attacker to cause the affected device to restart unexpectedly, resulting in a DoS condition.