Server headers and directory defaults usually show Apache server information.
This information can be used by hackers to learn about vulnerabilities on your server if the system is not updated.
You can mask server information as follows:

1. Log into server as root
2. Open /etc/httpd/conf/httpd.conf with an editor
3. Change the line ServerSignature on to ServerSignature Off
4. After that line, edit/add “ServerTokens Prod“
5. Save and exit.
6. Restart Apache:
   /etc/rc.d/init.d/httpd restart

Good luck!