A vulnerability in Cisco IOS XE Software could allow an authenticated, local attacker with level-15 privileges or an unauthenticated attacker with physical access to an affected device to execute persistent code at boot time and break the chain of trust. This vulnerability is due to improper validation of software packages. An attacker could exploit this vulnerability by placing a crafted file into a specific location on an affected device. A successful exploit could allow the attacker to execute persistent code on the underlying operating system. Because this vulnerability allows an attacker to bypass a major security feature of a device, Cisco has raised the Security Impact Rating (SIR) of this advisory from Medium to High.