How do Firewalls for Web Apps Work and Why is it Important?
A web application firewall, also called a WAF, is an online security system that looks for lousy web traffic between clients and a web application and blocks it. Find out more here.
Traditional security methods like intrusion detection systems (IDS), network firewalls, and intrusion prevention systems (IPS) do an excellent job of blocking unauthorized traffic and protecting your website at the network level. But these methods can't find and stop attacks like SQL injection, cross-site scripting (XSS), session hijacking, and others that happen because web applications have flaws.
The web application firewall is an effective and all-in-one security solution that can find threats by analyzing incoming HTTP requests before they reach the server. A WAF can find and stop malicious attacks hidden in website traffic that look safe and may have gotten past traditional security solutions. Organizations can also use web application firewalls to meet HIPAA and PCI-DSS standards.
How do firewalls for web apps work?
The web application firewall is set up as a hardware that works with the web server or as a server plugin that runs directly on the web server. A WAF stops all HTTP requests and looks at each before they are sent to the web server for further processing. It tries to trick the GET and POST requests while following the rules to find and block the bad traffic.
The WAF looks at the traffic and blocks it based on the settings you choose for it. It also challenges visitors by asking them to enter a CAPTCHA code or telling the server to copy an attack. The blocking and challenging options that are set stop any illegal traffic from reaching the web server.
The way a web application firewall works is based on the three security models below:
Whitelist (positive security model)
his model uses signatures and sometimes adds more logic to let only traffic through that meets certain criteria. For example, you could only let HTTP GET requests from a certain URL through and block all other traffic.
Blacklist (negative security model)
This model uses generic signatures to protect the website from known attacks. It also uses some specific signatures to stop attacks that could happen if the web application had a flaw.
Hybrid security model
This model can be used for both positive and negative security models.
A web application firewall is an excellent way to stop attacks on web applications, but this way of preventing attacks is still changing. Since there isn't a single tool that can handle all the security flaws in web-based apps, it's best to use more than one security solution.
WAF and DAST should be used together (Dynamic Application Security Testing). The DAST tools are made to look for signs of security holes in web apps already running. It is done by sending requests to a running web app that look like they came from a hacker.
A WAF also has other security options and ways to run that protect different kinds of websites. A WAF does more than protect a website. It also offers features like compression, caching, SSL acceleration, load balancing, and connection pooling, making a website more reliable and faster.