The SSL Zen WordPress plugin before 4.6.0 does not properly prevent directory listing of the private keys folder, as it only relies on the use of .htaccess to prevent visitors from accessing the site's generated private keys, which allows an attacker to read them if the site runs on a server who doesn't support .htaccess files, like NGINX.

The SSL Zen — SSL Certificate Installer & HTTPS Redirects WordPress plugin before 4.7.40 does not perform capability or nonce checks on a certificate-file download routine that runs early in the WordPress admin request lifecycle, allowing any authenticated user, including Subscribers, to download the site's TLS private key, certificates, and diagnostic logs.