Input validation

A vulnerability in Cisco IOS ROM Monitor (ROMMON) Software for Cisco Catalyst 6800 Series Switches could allow an unauthenticated, local attacker to bypass Cisco Secure Boot validation checks and load a compromised software image on an affected device. The vulnerability is due to the presence of a hidden command in the affected software. An attacker could exploit this vulnerability by connecting to an affected device via the console, forcing the device into ROMMON mode, and writing a malicious pattern to a specific memory address on the device. A successful exploit could allow the attacker to bypass signature validation checks by Cisco Secure Boot technology and load a compromised software image on the affected device. A compromised software image is any software image that has not been digitally signed by Cisco.