A vulnerability in the Cisco IOS XE ROM Monitor (ROMMON) Software for Cisco 4000 Series Integrated Services Routers, Cisco ASR 920 Series Aggregation Services Routers, Cisco ASR 1000 Series Aggregation Services Routers, and Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, physical attacker to break the chain of trust and load a compromised software image on an affected device. The vulnerability is due to the presence of a debugging configuration option in the affected software. An attacker could exploit this vulnerability by connecting to an affected device through the console, forcing the device into ROMMON mode, and writing a malicious pattern using that specific option on the device. A successful exploit could allow the attacker to break the chain of trust 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.

A vulnerability in Cisco Remote PHY Device Software could allow an authenticated, local attacker to execute commands on the underlying Linux shell of an affected device with root privileges. The vulnerability occurs because the affected software improperly sanitizes user-supplied input. An attacker who has valid administrator access to an affected device could exploit this vulnerability by supplying various CLI commands with crafted arguments. A successful exploit could allow the attacker to run arbitrary commands as the root user, allowing complete compromise of the system.