A vulnerability in Cisco IOS XE SD-WAN Software could allow an unauthenticated, physical attacker to bypass authentication and gain unrestricted access to the root shell of an affected device. The vulnerability exists because the affected software has insufficient authentication mechanisms for certain commands. An attacker could exploit this vulnerability by stopping the boot initialization of an affected device. A successful exploit could allow the attacker to bypass authentication and gain unrestricted access to the root shell of the affected device.