ModSecurity is a potent web application layer firewall for Apache web servers. It monitors the whole HTTP traffic to a website without affecting its operation and when it detects an intrusion attempt, it prevents it. The firewall additionally keeps a more detailed log for the website visitors than any web server does, so you'll be able to keep track of what's going on with your websites a lot better than if you rely simply on conventional logs. ModSecurity works with security rules based on which it prevents attacks. For instance, it detects if someone is attempting to log in to the administration area of a given script multiple times or if a request is sent to execute a file with a particular command. In these circumstances these attempts trigger the corresponding rules and the firewall software blocks the attempts right away, then records detailed information about them inside its logs. ModSecurity is amongst the very best software firewalls available and it could easily protect your web apps against a large number of threats and vulnerabilities, particularly if you don’t update them or their plugins often.