A vulnerability in the multicast DNS (mDNS) gateway feature of Cisco IOS XE Software for Wireless LAN Controllers (WLCs) could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition. This vulnerability is due to improper management of mDNS client entries. An attacker could exploit this vulnerability by connecting to the wireless network and sending a continuous stream of specific mDNS packets. A successful exploit could allow the attacker to cause the wireless controller to have high CPU utilization, which could lead to access points (APs) losing their connection to the controller and result in a DoS condition.