Learn How a Web Application Firewall Works

In today’s scenario, we can say that web hacking is a really rampant concern. It almost seems that on a daily basis we can hear major web hacking news that can impact a large corporation and its perceived cybersecurity defenses. People are left with the sense that if major corporate brands can be infiltrated, then how their information can be safe. One rather underrepresented form of website protection is implementing a web application firewall (WAF) into their web security profiles.

What is a Web Application Firewall (WAF) and its functionality?

Typically, there are various levels of communication in an IT system based on the Open Systems Interconnection (OSI) Model. More specifically, there are seven total layers of communication. One of the most highly targeted and sought after layers by web hackers is known as the Application layer (layer 7). However, the term “Application” in this context is referring to web applications, which are programs that allow users to submit data and interact with web pages. Gone are the days when websites were just merely static pages. These days, most websites allow users to customize settings or directly communicate with a web server by filling out personalized forms, submitting online payments, or access webmail in order to increase user engagement. This is all done through the wonderful work of web applications.

The communication between web applications and a web server occurs on the Application layer. Thus, the ultimate transfer of user data through web applications is what makes this layer one of the most targeted and highly vulnerable layers of the OSI model. As a result, web application firewalls were developed in order to help protect and filter out any malicious attacks toward the Application layer.

Next, it is important to note how a web application firewall functions.

The WAF is deployed as a hardware appliance, inline web server, or server plugin that runs directly on web servers. It intercepts all HTTP requests and analyzes each of them before they reach the web server for processing. It analyzes GET and POST requests while applying defined rules to identify and filter out illegitimate traffic.\

Depending on the selected WAF options, the WAF can block the traffic, challenge the visitor by asking them to input a CAPTCHA or instruct the server to simulate an attack. The blocking and challenging options prevent any illegitimate traffic from reaching the web server.

Different between WAF and Network Firewall

A WAF differs from a traditional firewall in that it does more than just block specific IP address or ports, it does a deeper inspection of web traffic looking for signs of a cross-site scripting attack or possible SQL injection. It is also customizable, allowing you to write rules specific to your application. For example, if your application is hosted on a platform that has a known vulnerability, but you have not had a chance to patch it yet, you can write a rule that looks for traffic attempting to exploit that vulnerability and block the traffic until you can get the vulnerable system patched.

Are All WAFs the Same?

Web application firewalls can differ in various ways. First, WAFs are available in hardware form, which typically requires a dedicated security staff to help install and subsequently monitor the hardware usage. Although this can be an expensive solution, it gives you or your online business the most comprehensive control over your own customizable web security environment. These days, many WAF vendors are offering cloud-based versions of their application security solutions, which makes it a much more convenient and easy to use solution to help secure their websites.

In addition to the physical form of the web application firewall itself, WAFs can differ by their detection technology. The majority of web security vendors utilize what is known as pattern matching or signature-based detection models as their sole detection method. This is a traditional form of protection where a web application firewall analyzes incoming web threats based on previous events or rules that occurred in the past. This effectively helps the WAF create an internal IP address white and blacklist to easily identify which attack source is exhibiting good or malicious behavior. However, this form of detection technology can be quite ineffective against several forms of attack, such as zero-day exploits or more innovative web attacks.

The New Wave of WAF Detection Technology

In order to deal the ever-changing world of cyber attacks, web application firewalls themselves had to become more intelligent. This need for more predictive and innovative technology spawned web security vendors to create a logic analysis based web application firewall software. Next generation WAF vendors have started to implement a non-signature detection methodology that aims to analyze web traffic based on a litany of search parameters and detection rules. This can be a more effective means of identifying malicious web attacks with the ability to increase accuracy, provide lower false positive readings, and intelligently predict new and modified web attacks.

We can understand the necessity of web security and most major media publications do not raise much awareness of cybersecurity. We can say, they do not provide enough adequate or specific instructions on how to properly protect your website and personal data from being exploited. So, whether you own an online business or have a casual website, it is important to ensure the protection of all personal or customer related data present on the site. In addition to following industry best practices to avoid web hacking (such as changing passwords often, avoiding suspicious email links, etc.), using a strong web application firewall can be the most effective way to safeguard the traffic that is redirected to your website. Get started today with proper website protection!

Authored By - Ayush Garg
TCS Cyber Security Practice

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