T1059.008 - Network Device CLI

Adversaries may abuse scripting or built-in command line interpreters (CLI) on network devices to execute malicious command and payloads. The CLI is the primary means through which users and administrators interact with the device in order to view system information, modify device operations, or perform diagnostic and administrative functions. CLIs typically contain various permission levels required for different commands.

Scripting interpreters automate tasks and extend functionality beyond the command set included in the network OS. The CLI and scripting interpreter are accessible through a direct console connection, or through remote means, such as telnet or SSH.

Adversaries can use the network CLI to change how network devices behave and operate. The CLI may be used to manipulate traffic flows to intercept or manipulate data, modify startup configuration parameters to load malicious system software, or to disable security features or logging to avoid detection.(Citation: Cisco Synful Knock Evolution)

Atomic Tests:

Currently, no tests are available for this technique.

Detection

Consider reviewing command history in either the console or as part of the running memory to determine if unauthorized or suspicious commands were used to modify device configuration.(Citation: Cisco IOS Software Integrity Assurance - Command History)

Consider comparing a copy of the network device configuration against a known-good version to discover unauthorized changes to the command interpreter. The same process can be accomplished through a comparison of the run-time memory, though this is non-trivial and may require assistance from the vendor.