4.2.15 Ensure sshd MaxAuthTries is configured

Information

The MaxAuthTries parameter specifies the maximum number of authentication attempts permitted per connection. When the login failure count reaches half the number, error messages will be written to the syslog file detailing the login failure.

Setting the MaxAuthTries parameter to a low number will minimize the risk of successful brute force attacks to the SSH server. While the recommended setting is 4, set the number based on site policy.

Solution

Edit the /etc/ssh/sshd_config file to set the parameter above any Include entries as follows:

MaxAuthTries 4

Note: First occurrence of a option takes precedence, Match set statements withstanding. If Include locations are enabled, used, and order of precedence is understood in your environment, the entry may be created in a file in Include location.

See Also

https://workbench.cisecurity.org/benchmarks/15289