The network element must be configured to timeout after 60 seconds or less for incomplete or broken SSH sessions.
An attacker may attempt to connect to the device using SSH by guessing the authentication method, encryption algorithm, and keys. Limiting the amount of time allowed for authenticating and negotiating the SSH session reduces the window of opportunity for the malicious user attempting to make a connection to the network element.
Configure the network devices so it will require a secure shell timeout of 60 seconds or less.
Review the configuration and verify the timeout is set for 60 seconds or less. The SSH service terminates the connection if protocol negotiation (that includes user authentication) is not complete within this timeout period. ip ssh time-out 60
Information Assurance Officer