What is a web application firewall (WAF)?

What does the web application firewall (WAF) do?

WAF is a security solution designed to protect web applications by continuously monitoring and filtering HTTP traffic between the web application and the internet. It protects against multiple threats such as SQL injection and cross-site (XXS) scripting, among others. At its core, a WAF works as a kind of protective layer that is put in between web applications and potentially malicious traffic.

How does a WAF Work?

To understand the significance of the role WAF plays in cybersecurity, we have to know how it works. In a nutshell, WAF network security, as already mentioned, works by examining the HTTP requests and responses against defined rules and policies. Here is a deep dive into the mechanisms behind WAF.

Inspection and filtering

The WAF is put between a user and a web application. So when a user sends a request to the web application, the WAF intercepts the requests passed to the web server and then inspects its contents, including headers, URLs, data payloads, and known attack signatures that might include SQL injection commands or XSS scripts.

Rule-based detection

WAF employs various rule sets to detect and stop threats. These rules define the normal and abnormal traffic behavior for a web application. For example, one of the rules could be to block the request that contains certain keywords or patterns in the message body that could be associated with SQL injection. The rules can be customized according to the needs of the web application.

Behavioral analysis

Apart from rule-based detection, some advanced WAFs will make use of various behavior analysis techniques. Fundamentally, this is the process of monitoring typical user behaviors to identify deviations that could be indicative of an attack. For example, if the user suddenly starts sending a large number of requests in a very short period, then probably a WAF will raise a red flag for a DDoS attack.

Real-time response

In the event of a threat, the WAF instantly acts to block the request from further passing on to the web application. Responsiveness in real-time is critical in suspending an attack before any serious damage occurs. Furthermore, WAFs can also generate alerts or log messages to inform administrators about identified threats and consequential actions that were performed to stop them.

By combining inspection, detection, and response mechanisms, a WAF can significantly increase the security of a network. Unsurprisingly, these days, WAFs are often a critical part of any comprehensive cybersecurity strategy.

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Why is a WAF important?

Safeguard sensitive information

The amount of sensitive information that exists in web applications is vast. Sensitive data includes personally identifiable data, financial details, and proprietary business data. In cases of successful cyberattacks and breaches, all such information is exposed. The role of WAF here is to prevent such incidents by blocking off malicious traffic to the web application and disallowing unauthorized access.

Avoid compliance fines and costs

Most industries are governed by stringent regulatory laws concerning data protection and privacy. Non-compliance with these regulations is your one-way ticket to heavy fines and lawsuits. A WAF makes it easier for businesses to comply with regulations by providing the much-needed security layer. Proactive measures taken to safeguard sensitive data mean peace of mind and better chances of avoiding hefty fines.

Preserve reputation

Today, a company's reputation is often related to its ability to protect customer data and maintain secure online services. A single successful cyber attack on an organization can put its reputation down the gutter once and for all. Implementing a WAF can mitigate such risk and further improve the reputation. Ultimately, most consumers trust a business, which means security not only in their PR statements but also in their actions.

Differences between WAF and network firewall

While WAFs and Network Firewalls both play a critical role in cybersecurity, they serve rather different purposes, and, as discussed, operate at different levels within a network. Here’s a rundown of the key differences between the two.

The role of WAFs

Security of web applications

As we discussed earlier, WAFs are built for the protection of web applications by filtering and analyzing HTTP traffic. HTTP is the protocol used for transferring data on the web, and WAFs focus on this traffic to defend against web-based attacks. WAFs can trace malicious activity against the application layer by analyzing the content of HTTP requests and responses since it works at Layer 7 of the OSI model.

Layer 7 protection

Layer 7 is where user interactions with software applications take place. As a part of their operation, WAFs track this layer for detailed content data about HTTP traffic. For example, an attacker could try to insert malicious code into a web form to gain unauthorized access to sensitive data; in such an instance, a WAF would detect and block that attempt immediately. This kind of sophisticated protection is critical for securing web applications against a variety of threats.

Should an attacker try to gain access to sensitive information by inserting malignant code in a web form, a WAF will block this attempt. This type of targeted protection is important to safeguard web applications from sophisticated threats.

The role of network firewalls

Protection of the network

A network firewall works toward protecting the entire network by managing incoming and outgoing traffic through filtering against a set of predefined security rules. It works at the network layer and the transport layer of the OSI model. These layers are responsible for proficient routing and reliable delivery of data packets in a given network. Network firewalls focus on threats like unauthorized access, DDoS attacks, and malware, ensuring that only legitimate traffic is allowed to pass through.

Layer 3 and 4 protection

Layer 3 is the network layer, including logical addressing of data packets to ensure that data sent from one device reaches the right destination, while Layer 4 is a transport layer responsible for the reliable transmission of data between devices. Network firewalls regulate the flow of data toward the destination based on IP address ports, and protocols. For example, they can be used to prevent an attacker from using an open port to access the network and so gain unauthorized access to network resources.

Bottom line

In an era where cyber threats are becoming increasingly sophisticated and pervasive, the importance of robust web security measures cannot be overstated. The implementation of a WAF is a vital component of contemporary web security. It provides the necessary tools to detect, prevent, and respond to web-based threats in real-time, ensuring the integrity and availability of web applications. As cyber threats continue to evolve, investing in a robust WAF solution will remain a critical priority for organizations seeking to protect their digital assets and maintain the trust of their users.

For comprehensive security, it's essential to protect not only your web applications but also your access credentials. Just as a WAF safeguards against web-based threats, a robust password management solution like NordPass Enterprise ensures that your organization’s passwords are protected from unauthorized access and are easily accessible at all times. NordPass provides features such as secure password sharing, automated password generation, and real-time breach monitoring, aligning perfectly with the goals of a WAF by adding an extra layer of security to your web infrastructure.