ModSecurity is an efficient firewall for Apache web servers that is used to prevent attacks toward web apps. It keeps track of the HTTP traffic to a given Internet site in real time and prevents any intrusion attempts as soon as it identifies them. The firewall relies on a set of rules to do this - for example, attempting to log in to a script administrator area without success several times sets off one rule, sending a request to execute a specific file which may result in accessing the Internet site triggers a different rule, and so on. ModSecurity is one of the best firewalls available and it will protect even scripts that aren't updated frequently because it can prevent attackers from using known exploits and security holes. Incredibly thorough data about every single intrusion attempt is recorded and the logs the firewall maintains are a lot more specific than the standard logs provided by the Apache server, so you can later take a look at them and decide if you need to take extra measures in order to boost the protection of your script-driven websites.