The ESXi host Secure Shell (SSH) daemon must set a timeout count on idle sessions.

Setting a timeout ensures that a user login will be terminated as soon as the "ClientAliveCountMax" is reached.

From an ESXi shell, run the following command:

# /usr/lib/vmware/openssh/bin/sshd -T|grep clientalivecountmax

Expected result:

clientalivecountmax 3

If the output does not match the expected result, this is a finding.

From an ESXi shell, add or correct the following line in "/etc/ssh/sshd_config":

ClientAliveCountMax 3