A vulnerability in motherboard console ports of line cards for Cisco ASR 1000 Series Aggregation Services Routers and Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, physical attacker to access an affected device's operating system. The vulnerability exists because an engineering console port is available on the motherboard of the affected line cards. An attacker could exploit this vulnerability by physically connecting to the console port on the line card. A successful exploit could allow the attacker to gain full access to the affected device's operating system. This vulnerability affects only Cisco ASR 1000 Series Routers that have removable line cards and Cisco cBR-8 Converged Broadband Routers, if they are running certain Cisco IOS XE 3.16 through 16.5 releases. Cisco Bug IDs: CSCvc65866, CSCve77132.