ModSecurity is an effective firewall for Apache web servers that's used to stop attacks towards web apps. It monitors the HTTP traffic to a particular website in real time and stops any intrusion attempts the moment it detects them. The firewall uses a set of rules to do that - as an illustration, trying to log in to a script administrator area unsuccessfully many times sets off one rule, sending a request to execute a certain file which may result in accessing the website triggers another rule, etc. ModSecurity is one of the best firewalls out there and it'll protect even scripts which are not updated regularly as it can prevent attackers from using known exploits and security holes. Very detailed data about each and every intrusion attempt is recorded and the logs the firewall keeps are a lot more comprehensive than the standard logs generated by the Apache server, so you may later analyze them and decide if you need to take more measures in order to enhance the protection of your script-driven websites.