To hide web server version number, server operating system details, installed Apache modules and more, open your Apache web server configuration file using your favorite editor:
$ sudo vi /etc/apache2/apache2.conf #Debian/Ubuntu systems
$ sudo vi /etc/httpd/conf/httpd.conf #RHEL/CentOS systems
And add/modify/append the lines below:
ServerTokens Prod
ServerSignature Off
Save the file, exit and restart your Apache web server like so:
$ sudo systemctl restart apache2 #SystemD
$ sudo service apache2 restart #SysVInit
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