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WAF vs. Firewall – What Are the Differences?

Web Application Firewall vs Network Firewall
Web Application Firewall vs Network Firewall (source: A10 Networks).

Individuals and companies alike are at risk of malicious cyber activity. In February 2023 alone, 106 data breaches were recorded and 29,582,356 records were compromised (source) – and these numbers seem to increase every year. 

Firewalls have been used for many years as a means of protecting computers against cyber threats. But what about Web Application Firewalls (WAFs) – Are they just as effective, and are there differences in their approach and capabilities? 

The two are not to be confused, as just using one or the other leaves major security holes in your system. Let's explore what makes them different – and why both contribute to a secure system.

Firewalls and WAFs 101

First, let's clarify what these two technologies are. A Web Application Firewall (WAF) and a traditional Firewall are two different types of security solutions that serve different purposes but are related in their overall goal of protecting networks and applications.

Firewalls

A firewall is a network security system that controls incoming and outgoing traffic based on predetermined security rules. It's designed to prevent unauthorized access to or from a private network. Firewalls analyze network traffic and apply rules to allow or block traffic based on a set of criteria such as IP addresses, ports, protocols, and other factors.

Some companies offer a firewall as part of an antivirus kit, like Norton or McAfee; others specifically offer a firewall as a standalone product, like Sophos Firewall. There are hardware options, too – but software is the most common. 

Ultimately, the goal of installing a firewall is to prevent any and all malware, attacks, and intrusions from accessing your computer.

WAFs 

A Web Application Firewall (WAF) is a specialized type of firewall that is designed specifically to protect web applications. The WAF sits between a web application and the internet and analyzes HTTP traffic to detect and block attacks such as cross-site scripting (XSS), SQL injection, and other web-based attacks. 

Unlike a traditional firewall, a WAF can understand the application layer (Layer 7) of the OSI model, which allows it to inspect and filter traffic based on specific characteristics of web application traffic.

What's the Difference?

While both firewalls and WAFs are designed to protect networks and applications from attacks, a WAF is specifically designed to protect web applications from web-based attacks, whereas a traditional firewall is designed to protect the network as a whole. 

WAFs offer a higher level of protection against web-based threats as they are able to inspect and filter web application traffic at the application layer. However, they cannot replace the need for a traditional firewall as firewalls offer protection at other network layers and can block other types of threats that a WAF may not detect.

Is WAF vs Firewall a Valid Contrast?

If you came into this article expecting to learn which product is better – firewalls or WAFs? – it's crucial to note that the two products do not go head-to-head. Instead, they complement one another to create a complete security package, and both are necessary for complete protection. 

Firewalls and WAFs: Key Use Cases

Perhaps the most drastic difference between traditional firewalls and WAFs is their use cases. Firewalls and WAFs are often conflated since they're both referred to as ‘firewalls' – but the way they are used, and who they are used by, are different.

Traditional Firewalls

Example – Microsoft Defender Firewall is a built-in network security feature in Windows operating systems. It provides a layer of protection against unwanted or malicious network traffic.

To the individual, a firewall is a fairly standard piece of software or hardware designed to protect one's computer or network from malicious activity. Most personal computers come with a built-in firewall ready to go; they're not always as strong as those available with an antivirus package, but they provide basic protection.

A personal computer firewall works by monitoring incoming network traffic and blocking any suspicious activity. It's designed to detect malicious traffic, such as viruses or malware, and block it from entering the computer.

For businesses, traditional firewalls are used to protect all the computers connected to a network (we call these ‘network firewalls‘). Mid-to-large size businesses typically need to invest in enterprise-scale firewalls to protect all of their devices and operations adequately. 

Web App Firewalls

Cloudflare WAF
Example – Cloudflare WAF is designed to protect web applications (ie. your WordPress website) from common attacks such as SQL injection, cross-site scripting (XSS), etc. It does this by inspecting the traffic to your website and applying a set of rules to block or allow specific types of requests.

While WAFs do have an indirect impact on individual web users, they are primarily used by companies running web applications. An app like eBay, for instance, collects sensitive data from millions upon millions of users – so it (and similar apps) needs a security system designed to protect the application itself.

A WAF is also designed specifically to detect and prevent attacks like cross-site scripting (XSS) and SQL injection. A traditional firewall may be able to detect some of these attacks, but a WAF will have much more information about the structure of web applications, making it better equipped to recognize the malicious activity. 

Not all web applications are used by the wider public like eBay or Spotify – a lot of the time, WAFs are implemented for internal corporate applications. For instance, a company may use a web-based application to store customer data or employee records – and in these cases, a WAF is essential for additional security.

Note that WAFs are never implemented by individual web users. Even so, they work in favor of web users by protecting the data we give to web applications. If Instagram didn't have an incredibly strong WAF, for example, our passwords, photographs, and personal information could be at risk.

Risks of Not Using A Firewall vs WAF

On a business level, attacks can be incredibly costly and damaging – particularly when it comes to corporate applications like employee records or customer databases. A breach in one of these would likely result in significant financial losses as well as reputational damage, so firewalls and WAFs are essential for keeping businesses safe from cyber attacks.

Neglecting to use a network firewall leaves your business vulnerable to:

  • Privilege escalation. If an attacker gains access to your network, they can exploit any security holes to gain higher levels of privilege and break into adjacent systems. 
  • Unauthorized access. Attackers can use vulnerabilities such as credential theft, social engineering, or compromised systems to gain access to the network. 
  • MITM attacks. Short for man-in-the-middle, MITM attackers intercept your company's network traffic and use it to gain access or steal sensitive data on the spot. 

Failing to implement a WAF for your applications is a mistake, too, with risks such as:

  • SQL injection. Attackers can inject malicious code into your application's database, allowing them to steal data or manipulate the system. This is one of the most common web attacks that WAFs can detect and protect against. 
  • Cross-site scripting. By using malicious scripts, attackers can hijack users' sessions or inject malware into the application for other nefarious purposes. 
  • Denial of service. Applications only have a certain amount of resources available to them, and a malicious actor can exploit this to overwhelm your system with requests and make it unusable. The attacker can then strike while the defenses are down. 

As you can see, firewalls and WAFs protect against different threats – so they're both crucial for keeping your business safe. 

Next-Generation Firewalls

Over the years, we've recognized the fact that companies need both network firewalls and WAFs to remain completely secure – and businesses also find this incredibly annoying. It's frustrating to invest in two different products and manage them separately. 

That's why many businesses are turning to Next-Generation Firewalls (NGFWs). These combine the capabilities of both a firewall and WAF into one product so that companies can save money and simplify their security infrastructure. NGFWs also offer additional features such as deep packet inspection, intrusion prevention systems (IPS), and application whitelisting, which provide businesses with an even higher level of protection. 

Key Takeaways

Firewalls and WAFs are both essential for keeping businesses secure from cyber attacks. A firewall protects against unauthorized access, privilege escalation, and man-in-the-middle attacks, while a WAF guards against SQL injection, cross-site scripting, and denial of service threats. 

When it comes to the conversation around WAFs vs firewalls, keep in mind that the two are complementary – not in competition with one another. They're simply two parts of a broader set of corporate security measures. A business using web applications for either internal or customer-facing use would benefit from both a firewall and WAF. 

Individuals, on the other hand, don't choose to implement a WAF since they don't typically manage servers hosting data or applications. They'll implement a traditional network firewall to protect their home or personal devices from cyber attacks. 

Businesses can also opt for a next-generation firewall, which combines the features of both firewalls and WAFs into one product. This allows businesses to save money and simplify their security infrastructure while still providing the same level of protection.

Whether you're looking for a traditional firewall, WAF or NGFW, there are plenty of great security products on the market that can keep your business safe from cyber-attacks. Make the most of free trials and product demos to find the right solution for your business.

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Article by Timothy Shim

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