WAF – Web Application Firewall

What is WAF (Web application firewall)?

A web application firewall (WAF) protects web applications from application-layer attacks such as cross-site scripting (XSS), SQL injection, and cookie poisoning. Attacks on apps are the leading cause of breaches—they are the gateway to your valuable data. With the suitable WAF in place, you can block the array of attacks that aim to exfiltrate that data by compromising your systems.

Web Application Firewall

How does a web application firewall (WAF) work?

The web application firewall (WAF) protects your web apps by filtering, monitoring, and blocking any malicious HTTP/S traffic traveling to the web application and preventing unauthorized data from leaving the app. It uses a set of rules and procedures to determine what kind of traffic is good or bad. In addition, the WAF acts as an intermediary to protect the web application server from a potentially malicious client as a proxy server. As a reverse proxy, the WAF is the one that covers the web application server.

Webs are the perfect choice for a WAF appliance. They’re easy to deploy and maintain and fit for web-scale operations. In addition, a policy can be customized to meet the unique needs of your web application or set of web applications. While many WAFs require you to update your policies regularly to keep up with changes in emerging threats, advances in machine learning allow some WAFs to do this automatically. Automation is a critical component of your security posture, and the growing threat landscape is making it more critical than ever before.

The difference between a web application firewall (WAF), an intrusion prevention system (IPS), and a next-generation firewall (NGFW).

An IP address is used to identify an individual computer or network in cybersecurity uniquely. A WAF is a web application firewall, and an NGFW is a next-generation firewall. What are the differences between them? The IPS is a more broadly focused security product. Security policies typically include security-focused processes that are often signature and policy-based. They generally are well established by large companies, and you can easily incorporate them into your infrastructure.

The IPS establishes a standard based on the database and policies, then sends alerts when any traffic deviates from the average. Over time, a signature grows in size and complexity as new vulnerabilities are discovered. IPS protects traffic across a range of protocol types such as DNS, SMTP, TELNET, RDP, SSH, and FTP. When IPS operates and protects layers 3 and 4, the network and session layers typically use and protect only layers 3 and 4. IPS sometimes provides limited protection at the application layer.
The web application firewall (WAF) is a powerful security tool designed to analyze each HTTP/S request at the application layer. It protects the application layer. Most applications and websites are not only user- or session-aware but also aware of the application services that are offered. Because of this, a WAF acts as an intermediary between the user and the app, analyzing all communications before they reach the app or the user. With traditional WAFs, you are restricted to performing only those actions allowed by your security policy.

When organizations choose to use WAFs for their applications, they often focus on the OWASP Top 10, which are the most-seen application vulnerabilities. These are the Top 10 currently. They are

  • Injection attacks
  • Broken Authentication
  • Sensitive data exposure
  • XML External Entities (XXE)
  • Broken Access control
  • Security misconfigurations
  • Cross-Site Scripting (XSS)
  • Insecure Deserialization

The next-generation firewall monitors the traffic going out to the Internet. It monitors websites, email accounts, and SaaS. It’s an important concept to understand in developing applications, especially mobile apps. With a UGFW, you enforce policy based on who is doing what with what assets, so you can apply content filters, anti-virus/anti-malware, and more in conjunction with URL filtering. Although a web application firewall (WAF) is typically a reverse proxy (used by servers), network-based firewalls (NFW) are often forward proxies (used by clients such as a browser).

There are several ways to deploy a WAF: Where you want to deploy it and the services needed. Do you want to manage it yourself, or do you want to outsource that management? Is it better to run your web application firewall (WAF) in the cloud or data center? How you want to deploy will help determine which WAF is best for you. Choose from the options below.

WAF Deployment Modes:

  • Cloud-based + Fully Managed as a Service—this is an excellent option if you require the fastest, most hassle-free way to get WAF in front of your apps (especially if you have limited in-house security/IT resources)
  • Cloud-based + Self-Managed—get all the flexibility and security policy portability of the cloud while retaining control of traffic management and security policy settings.
  • Cloud-based + Auto-Provisioned—this is the easiest way to get started with a WAF in the cloud, deploying security policy efficiently and cost-effectively.
  • On-premises Advanced WAF (virtual or hardware appliance) meets the most demanding deployment requirements where flexibility, performance, and more advanced security concerns are mission-critical.