A vulnerability in the authentication and authorization checking mechanisms of Cisco Wireless LAN Controller (WLC) Software could allow an authenticated, adjacent attacker to gain network access to a Cisco TrustSec domain. Under normal circumstances, this access should be prohibited. The vulnerability is due to the dynamic assignment of Security Group Tags (SGTs) during a wireless roam from one Service Set Identifier (SSID) to another within the Cisco TrustSec domain. An attacker could exploit this vulnerability by attempting to acquire an SGT from other SSIDs within the domain. Successful exploitation could allow the attacker to gain privileged network access that should be prohibited under normal circumstances.