A vulnerability in the Cisco TrustSec (CTS) Protected Access Credential (PAC) provisioning module of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to improper validation of attributes in RADIUS messages. An attacker could exploit this vulnerability by sending a malicious RADIUS message to an affected device while the device is in a specific state.