What are the benefits and drawbacks of using a web application firewall over a network firewall?

1 What is a WAF?

A WAF is a firewall that operates at the application layer of the network stack. It monitors and analyzes the HTTP requests and responses that are exchanged between the web server and the client. It can detect and prevent attacks that target the logic, functionality, or data of the web application, such as SQL injection, cross-site scripting, or session hijacking. A WAF can also enforce security policies, such as encryption, authentication, or rate limiting.

2 What is a network firewall?

A network firewall is a firewall that operates at the network layer or the transport layer of the network stack. It monitors and controls the traffic that flows between different networks or hosts. It can filter and block packets based on their source and destination IP addresses, ports, protocols, or flags. It can protect the network infrastructure from attacks that target the availability, integrity, or confidentiality of the network, such as denial-of-service, port scanning, or spoofing.

3 Benefits of using a WAF

Using a WAF has several advantages over using a network firewall for web application security. First, a WAF can provide more granular and specific protection for the web application, as it can inspect the content and context of the HTTP traffic. It can also adapt to the changing threats and vulnerabilities of the web application, as it can be updated with new rules and signatures. Second, a WAF can reduce the workload and complexity of the web server, as it can offload some tasks, such as encryption, compression, or caching. Third, a WAF can improve the performance and scalability of the web application, as it can balance the load, optimize the bandwidth, or handle peak traffic.

4 Drawbacks of using a WAF

Using a WAF also has some disadvantages over using a network firewall for web application security. First, a WAF can introduce some latency and overhead to the HTTP traffic, as it has to process and analyze each request and response. It can also affect the functionality and usability of the web application, as it may block some legitimate traffic or trigger some false positives. Second, a WAF can be bypassed or evaded by some sophisticated attacks, such as obfuscation, encryption, or fragmentation. It can also be vulnerable to some attacks itself, such as brute force, flooding, or poisoning. Third, a WAF can be costly and complex to deploy and maintain, as it requires specialized hardware, software, or services. It also requires constant monitoring, tuning, and updating to keep up with the web application changes and security requirements.

5 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?