What is WAF?

Web Application Firewall or WAF protects your website from spam attacks by filtering and monitoring HTTP traffic coming from the Internet. WAF offers 7 layers of defense as in the OSI model and secures your site from attacks such as cross-site forgery, cross-site-scripting (XSS), file inclusion, and SQL injection.

But it is not a full-proof solution for all the types of spam attacks. It can mitigate a specific range of attack vectors and work with other tools/software to create a highly secure environment for your website. 

How does a Web Application Firewall Work?

WAF acts as a protective shield between the website and the internet. It functions as a reverse proxy that protects your server from unwanted exposure by having visitors pass through the firewall before reaching the server. 

How does WAF work?

Web Application firewall functions via a set of rules known as policies. These policies main objective is to protect the website against vulnerabilities by filtering out malicious traffic.

The real value of WAF is defined in terms of speed and east which these rules can be modified and implemented. This results in faster response to different kinds of attack vectors during a malware attack. 

What is the difference between blacklist and whitelist WAFs?

Blacklist Firewall- It operates against common attacks using a negative security model. It can be understood with the help of an example. A blacklist firewall acts LIKE a club bouncer, he or she doesn’t allow anyone who doesn’t meet the dress code to enter the club.

Whitelist Firewall- It allows only traffic that has been pre-approved to enter the website (positive security model). For example, an exclusive party bouncer, he or she allows entry to people who are on the list.

The recommended method is to implement a hybrid security model which offers advantages of both the types of firewalls.

What is the difference between a Firewall and a Web Application Firewall?

A traditional firewall safeguards the flow of data between servers while WAF filter traffic for a specific web application. Network firewalls and WAF complement each other and can work together.

The traditional firewalls help in blocking bad traffic present at layer 3 and layer 7 of the OSI model. They include network firewalls, intrusion detection systems (IDS) and intrusion prevention systems (IPS). Network firewalls cannot detect attacks in the web applications as they occur on layer 7 (HTTP) of the OSI model.

Different ways to deploy a WAF

You can deploy WAF in many ways depending upon where your applications are deployed, the services and performance you require, how you want to manage it, and the level of architectural flexibility. Different types of deployment models are given below:-

WAF Deployment Modes:-

  • Cloud-based + Fully managed by hosting provider- It is a great choice if you are not a technical person and require the fastest and easiest way to deploy WAF in front of your web application.
  • Cloud-based + Self Managed- You can for this type of deployment model to get the flexibility and security policy portability of the cloud. You retain control of traffic management and security policy settings.
  • Cloud-based + Auto-Provisioned-  It is a cost-efficient and easy way to deploy a WAF and its security policy in the cloud.
  • On-premises Advanced WAF (virtual or hardware appliance)- It is one of the most demanding deployments that is done when flexibility, performance, and more advanced security concerns are crucial. 

Advantages of WAF

Web Application Firewall offers greater visibility into sensitive application data that is communicated using the HTTP application layer.

It can prevent application layer attacks that usually pass through traditional network firewalls, including the following:

  • Cross-site scripting (XSS) attacks- It allows hackers to inject and execute malicious scripts in the user’s browser.
  • Structured Query Language (SQL) injection attacks- These types of attacks can affect any web application that uses an SQL database and permits spammers to access and potentially alter the sensitive data.
  • Web session hacking- It allows hackers to hijack a session ID and behave as an authorized user. A session ID is usually stored within a cookie or Uniform Resource Locator (URL).
  • Distributed denial-of-service (DDoS) attacks- These types of attacks overwhelm a network by flooding it with traffic until it is not able to serve its users. Both traditional firewalls and WAFs can handle this attack type but in their own different ways. 

Advantages of WAF

Another advantage of WAF is that you can defend web-based applications without having to access the application’s source code. While host-based WAF can be integrated into the application code, cloud-hosted WAF can defend applications without access.

In addition, WAF in the cloud is easy to deploy and manage and provides a quick virtual patch solution that allows users to quickly customize settings to accommodate newly detected threats.

Are WAFs alone sufficient to ensure web application security?

WAF offers an application security element, but itself is not enough to protect the web application. Due to poor signal-to-noise ratios, complex maintenance, and lack of visibility of vulnerabilities and applications, you cannot rely on WAFs to meet all application security needs.

However, it is well suited for defending against basic types of application threats and can provide value if used in depth of defense methods with elements such as RASPs and CSPs.

ServerGuy offers complete security solutions to protect your web application or website including traditional firewalls, WAFs, custom security monitoring and protection. You can leave a comment below or contact us directly, we will revert back as soon as possible.

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