A vulnerability in Cisco IOS XE Software could allow an authenticated, local attacker with high privileges or an unauthenticated attacker with physical access to the device to open a debugging console. The vulnerability is due to insufficient command authorization restrictions. An attacker could exploit this vulnerability by running commands on the hardware platform to open a debugging console. A successful exploit could allow the attacker to access a debugging console.
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-XE-BLKH-Ouvrnf2s