The Photon operating system must configure Secure Shell (SSH) to limit the number of allowed login attempts per connection.

By setting the login attempt limit to a low value, an attacker will be forced to reconnect frequently, which severely limits the speed and effectiveness of brute-force attacks.

At the command line, run the following command to verify the running configuration of sshd:

# sshd -T|&grep -i MaxAuthTries

Example result:

maxauthtries 6

If "MaxAuthTries" is not set to "6", this is a finding.

Navigate to and open:

/etc/ssh/sshd_config

Ensure the "MaxAuthTries" line is uncommented and set to the following:

MaxAuthTries 6

At the command line, run the following command:

# systemctl restart sshd.service