Always make sure that installed web servers and the content management system (CMS) are up to date. Some CMS allow you to hide the version information. Use this feature if it is available. The WordPress Plug-in "Hide My WP (German only)" may be interesting for you.
Further example for WordPress: In order to prevent attackers or hackers from reading the WordPress version directly, you can add the following line of code at the very end of the file functions.php: