Five years after Cisco issued its first warning, the Smart Install protocol is still being utilized in assaults, and there are around 18,000 internet-exposed devices that might be targeted by hackers. Smart Install is a plug-and-play configuration and image-management technology from Cisco that allows new switches to be deployed with zero-touch. Smart Install can be extremely important to organizations, but it can also be a significant security concern. 

A Smart Install network consists of a group of networking devices known as clients that are served by a common Layer 3 switch or router that serves as a director. You can use the Zero-Touch Installation process in a Smart Install network to install new access layer switches without the help of the network administrator. The director acts as a central management point for client switch images and configuration. When a new client switch is added to the network, the director immediately recognizes it and determines which Cisco IOS image and configuration file should be downloaded. 

The function remains enabled and can be accessed without authentication once a device has been set up via Smart Install. Malicious actors have been able to remotely target devices with Smart Install enabled, including reloading devices, loading a new operating system image, and running arbitrary commands with elevated privileges. 

After an exploitation tool was made public in 2016, Cisco issued a warning on the misuse of Smart Install. In 2017 and 2018, the company sent more alerts, identifying hundreds of thousands of vulnerable devices, including those in critical infrastructure organizations. In 2018, it was revealed that hacktivists targeted the Smart Install function in assaults on Cisco switches in Iran and Russia as part of an ostensibly pro-US attack, as well as a state-sponsored cyberespionage group affiliated to Russia. 

In 2016, the number of networking equipment vulnerable to Smart Install assaults surpassed 250,000, but by 2018 it had reduced to 168,000. The Shadowserver Foundation is still keeping track of the number of potentially susceptible devices, reporting that almost 18,000 are currently online, including many in North America, South Korea, the United Kingdom, India, and Russia. 

Last month, Lumen Technologies' Black Lotus Labs cybersecurity unit discovered that a hacktivist group had compromised at least 100 internet-exposed routers belonging to both public and private sector entities, most of which were based in the United States.