Multiple vulnerabilities in the initialization routines that are executed during bootup of Cisco IOS XE Software for Cisco ASR 900 Series Aggregation Services Routers with a Route Switch Processor 3 (RSP3) installed could allow an authenticated, local attacker with high privileges to execute persistent code at bootup and break the chain of trust. These vulnerabilities are due to incorrect validations by boot scripts when specific ROM monitor (ROMMON) variables are set. An attacker could exploit these vulnerabilities by copying a specific file to the local file system of an affected device and defining specific ROMMON variables. A successful exploit could allow the attacker to run arbitrary code on the underlying operating system (OS) with root privileges. To exploit these vulnerabilities, an attacker would need to have access to the root shell on the device or have physical access to the device.
