Login: Exponential Backoff is set

Information

A malicious user may attempt to gain CLI access by means of a dictionary attack using a script to automatically attempt to login as an 'admin' user and using a dictionary list to test all possible passwords. Using the 'exponential-backoff' feature in the config>system>login-control context SR OS increases the delay between login attempts exponentially to mitigate attacks.

When trying to access the router, the user is only allowed three attempts per session, by default, to login to the system before the connectivity session is terminated. It is during that single connectivity session that the exponential backoff is utilized. Each time an invalid password is entered for a login account name, a delay is inserted before the next display of the login/password prompt. The first delay is 1 second, and each subsequent delay is 2 times the last delay (for example, 1 second, 2 seconds, 4 seconds). Once the connectivity session is terminated after the third failed login attempt, the exponential backoff timer is reset to 1 second.

Solution

Run the following command on the device to enable exponential backoff: configure system login-control exponential-backoff

See Also

https://infoproducts.alcatel-lucent.com/aces/cgi-bin/dbaccessfilename.cgi/9305050101_V1_SR-OS Security Best Practices v2.0.pdf