Strict-Transport-Security Missing Max-Age (Non-compliant with Spec)

A HTTP Strict Transport Security (HSTS) header was found, but it is missing the max-age directive (or the directive is missing a value). See RFC 6797 for further details.

HTTP Strict Transport Security (HSTS) is a web security policy mechanism whereby a web server declares that complying user agents (such as a web browser) are to interact with it using only secure HTTPS connections (i.e. HTTP layered over TLS/SSL).

Review the configuration of this control. Ensure that your web server, application server, load balancer, etc. is configured to set Strict-Transport-Security with an appropriate max-age value.