Exploring the Pros and Cons of Web Application Firewalls (WAFs)

Over the last few years, web application attacks have become one of the leading causes of data breaches, making web application security increasingly important for overall security posture. In fact, web application attacks were involved in 26% of all breaches in 2022 according to the 2022 Verizon DBIR, making them the second most common attack pattern that year. As a result, Web Application Firewalls (WAFs) have become a focal point of some security conversations. 

What is a web application firewall (WAF)?

A web application firewall (WAF) monitors, filters and blocks (if necessary) HTTP traffic as it travels between a web application and a requestor via the internet. Much like how TSA controls who passes through security checkpoints at an airport, WAFs protect web systems against known and unknown threats and vulnerabilities in today’s security threat landscape.

WAFs can be used to inspect, detect and prevent attacks such as malware infections, zero-day exploits, impersonations, and potentially other similar threats, whether running as a network appliance, server plugin or cloud service. 

What is the difference between a web application firewall (WAF) and a regular firewall?

WAFs and standard firewalls  differ not only in the type of protection they offer, but in overall function. For starters, a WAF is primarily focused on the security of an application, whereas the traditional firewall is focused on the security of a network. 

A traditional firewall protects a secured, local-area network from unauthorized access to prevent the risk of attacks. Its primary job is to separate secured zones from less secure zones, controlling all communications between the two. 

WAFs, on the other hand, sit between external users and web applications to analyze all HTTP communication. It then detects and blocks malicious requests (based on a list of known attack types) before they reach the user, securing business-critical web applications and servers from zero-day threats and other application-layer attacks. 

What are the advantages of using a WAF?

As web application attacks continue to grow, implementing a solution (or solutions) that will effectively protect an organization’s digital assets is critical. WAFs offer a number of advanced capabilities that have proven to strengthen web application security. For example WAFs provide advanced threat prevention capabilities, and they also give administrators the flexibility needed to respond to sophisticated attacks with real-time insights into application traffic, performance, security and threat landscape.

What are the disadvantages of WAFs?

As with any solution, there are also disadvantages to implementing a WAF into a security strategy. WAFs operate through a set of rules or policies, known as WAF Rules, that aim to protect against vulnerabilities by filtering out malicious traffic. These rules must be updated frequently, which can make WAFs complex to deploy. Cloud architectures and rapid rates of change in cloud environments also make it difficult to keep WAFs effective.

While the speed and ease with which WAF rules can be implemented allow for quicker response times to varying attack vectors, they also require regular maintenance whenever additions or updates are made to an application. As a result, WAFs are subject to a high degree of false positive alarms, as the protected applications are constantly changing and requiring different rules for traffic over time. 

WAFs in the current threat landscape

While WAFs provide protection against numerous sophisticated attacks, like SQL injection, cross-site scripting (XSS) and other application-specific attacks, they can’t shield web assets from all attacks. For example, most WAFs can’t protect against malicious bots. Some bots use direct attacks that WAFs are designed to identify and block, but many abuse legitimate business logic that WAFs simply are not designed to identify. This is why it is incredibly important to have a well rounded security stack that includes other security solutions that complement a WAF (such as bot management software, in this case.)

Introduction to FireTail’s API Security Platform vs. WAFs

After analyzing the root cause of known application programming interface (API) breaches, FireTail engineered a hybrid approach to API security: an open source library that protects programmable interfaces with inline API call evaluation and blocking, and cloud-based API security posture management, centralized audit trail, and detection and response capabilities. We are the only company offering these capabilities together.

The four most common API attack vectors include: broken authorization logic, flawed authentication controls, security misconfigurations, and injections making APIs misbehave. Most approaches to API security are based around network traffic analysis or WAFs; yet both of those approaches fail to stop the most common API attack vectors because the attacks look like normal traffic. In future blog posts, we will get into further detail about how FireTail’s approach goes above and beyond traditional WAFs.

To learn more about the key benefits of FireTail’s API security platform, including the ability to block and track the top API attack vectors in real-time, please contact us.

PS - some other great resources on this topic include:

https://www.techtarget.com/searchsecurity/definition/Web-application-firewall-WAF