[…]Instead, security has to be comprehensive and pervasive on every network device (switches, routers, etc.) as hackers get more sophisticated and unpredictable and capable of exploiting both hardware and software vulnerabilities. These attackers, with cutting-edge techniques, can access memory chips, use tools to extract the contents of those chips and then use the content to build/configure systems to act as imposters on the customer’s networrk. Bottom line – Malware can be installed on a router or switch. Are you protected ?[…]
https://blogs.cisco.com/datacenter/building-data-center-trustworthy-systems
Firmware Security 