WAF in Cybersecurity means Web Application Firewall which helps to monitor and block the HTTP traffic that travels from the web application or website. A WAF can work as a cloud-based or host-based that is integrated through reverse proxy and placed in front of applications and websites. While running as a cloud service or network appliance, the WAF monitors each packet and uses a Layer 7 web application to filter out harmful traffic that hackers or cyber thieves can exploit.
Web application firewalls act as one of the most effective security tools that companies use to safeguard web systems against malware infections and other harmful threats. It can find security flaws with customized inspections that other network firewalls usually cannot detect easily. Companies that provide online services or sell products online can make the most out of the this solution. For example, if you own an ecommerce company or are involved in online banking, then you can implement this solution to protect your business against potential security threats.
How WAF works?
It analyzes the HTTP requests and applies specific security measures to identify which part is malicious and take the right action accordingly. WAF examines the main parts of HTTP traffic, which are POST and GET requests. POST requests send data to the server, while GET requests retrieve data. WAF uses one of the following methods to assess and filter the traffic from HTTP requests.
Whitelisting
The Web application firewalls only allows requests to be bypassed, which can be trusted and blocks malicious requests by default. It has a list of IP addresses that are safe. This process is known as Whitelisting, which is less resource-intensive than other methods.
Blacklisting
Blacklisting blocks malicious web traffic of websites and applications by using the present signatures. It has specific rules that detect malicious packets. Blacklisting receives plenty of traffic from different IP addresses that are not known to be benign or malicious, so it makes this method suitable for web apps and public websites.
Hybrid Security
The hybrid security framework uses components of whitelisting and blacklisting to identify the potential vulnerabilities and malicious activities that can enter the website or web application through HTTP traffic.
Importance of Web Application Firewall
WAF holds special importance in the current era, as a number of companies are increasingly growing and are doing online business, so they need to prevent data leakage. For this, they need WAF solutions to secure data like customer records and bank and credit card information that are stored in the companies’ databases.
Hackers target these applications to gain access to the associated data. Banks use this system on a large scale to protect cardholders’ data. Also, banks need to follow the standard set of policies by installing a firewall. Due to continuous technological advancements, organizations are now integrating mobile applications and the Internet of Things. The large number of online transactions also takes place daily, so this service is crucial for the security of modern-day businesses.
Types of Web Application Firewall
There are different types of WAFs that you must know to understand the role of each component and how they work. Let’s find out about it.
Network-based WAF
The network-based WAFs are installed onsite through a particular appliance, which is the hardware-based firewall. It reduces latency and allows the implementation of rules across different appliances. One of the biggest downsides of this type of firewall is the cost, as it can be expensive to manage the maintenance costs, especially for startups.
Host-based WAF
The host-based WAF can be integrated into the application code, which helps to reduce the cost and provide better customization options. However, it can be challenging to manage these types of firewalls because they need application libraries and server resources to work properly. These types of WAFs also need more staff resources, such as system analysts, developers, and DevOps, and can be costly to handle.
Cloud-hosted WAFs
Cloud-hosted firewall offer a cost-efficient option for companies that need minimal management resources. The cloud-based firewalls are easy to integrate and also available on subscription. They also need a simple domain system to redirect the application traffic. It can be difficult to filter the traffic with a third-party provider, as this strategy enables applications to be protected across different hosting locations. These third parties also have the latest threat intelligence and can quickly identify and block potential threats.
Features of Web Application Firewall
WAF offers different benefits compared to traditional firewalls, as it provides better security and visibility for sensitive applications and websites. Here are some of the common features that will help you understand how Web application firewalls safeguards websites and web applications from potential threats.
Safety from Web Application Attacks
This solution can identify and mitigate common web application attacks like SQL injection and cross-site scripting by blocking malicious traffic.
Application Profiling WAFs
Can also detect and deny malicious requests with application profiling that analyzes the structure of the application, URLs, and the relevant data types.
Monitoring and Logging
This type of firewalls have detailed logging and monitoring capabilities that are required for the investigations of security breach incidents. You can consider the example of Amazon Web Services, which offers different monitoring and logging options for its WAF resources like AWS CloudTrail and AWS CloudWatch.
Customization
With a web application firewall, security rules can be deployed to application traffic. It allows companies to control WAF according to their specific needs and avoid situations where they miss genuine traffic. Better Compliance Web application firewalls can improve compliance by providing an extra layer of defense against web attacks that can reveal sensitive data to attackers.
Flexibility and Scalability
These firewalls are scalable and can handle websites and applications with high traffic. It also gives the flexibility of integrating different configurations in different types of environments, including cloud-based settings.
Solid Defense Mechanism without Source Code Access
The WAF can protect web-based applications without having access to source code. The host-based WAF can be deployed to the application code, while cloud-hosted WAF can protect the application without access. Furthermore, cloud WAF is easy to handle, as it offers quick virtual patching options that allow users to customize their settings according to the latest threats that are detected.
Content Delivery Networks
This type of solutions is configured with the network edge, which means that cloud-hosted WAFs can offer content delivery networks (CDN) to the website’s cache, which decreases the load times. It also integrates the CDN with different dispersed points to reduce the latency of websites.
AI-based Traffic Analysis
It can also work on AI-based algorithms by using behavioral patterns to identify suspicious activities that can indicate a potential attack.
Web Application Firewall Examples
To better understand the web application firewall, you must understand that commercial and open-source WAFs are used according to the requirements of companies. Here are some examples of web application firewalls that will help you understand how commercial and open-source vendors use it.
Let’s find out first about the commercial WAFs.
Barracuda
The Barracuda WAF provides protection against data leakage that helps companies safeguard their valuable business data.
Cloudflare
Cloudflare provides protection against attacks like SQL injections and zero-day attacks. It is a cloud-based WAF that does not need any software or hardware installation.
F5
F5 WAF protects websites and applications that are run in the cloud and hybrid IT workplaces. It has a browser-based interface that supports network device configuration and streamlines security policy management. Also, it provides adherence to important legal requirements and protects applications from different vulnerabilities.
Now, let’s find out about different open-source WAFs.
ModSecurity
TrustWave offers this WAF, which is supported by Apache. ModSecurity applies certain rules to prevent cyber-attacks, such as trojans and cross-site scripting, which help to prevent information leakage.
WebKnight
Aqtronix offers this WAF, which is supported by Microsoft IIS. It secures web servers, blocks bad requests, and provides protection against SQL injections, encoding attacks, and buffer overflows.
Naxsi
This WAF is used for Ngnix servers that help to protect applications against SQL injection attacks and cross-scripting.
Comparison of WAF with IPS, NGFW, RASP, and Firewall
Companies use different security technologies according to their requirements to protect their networks and systems. Some of the common security technologies mentioned below, including WAF, will help you understand their differences and how they work.
WAF
The purpose of a Web Application Firewall (WAF) is to safeguard web applications by filtering, monitoring, and blocking HTTP(S) requests. It focuses on protecting against application-specific attacks such as SQL injections, cross-site scripting (XSS), and cross-site request forgeries (CSRF) and operates at the application layer (Layer 7 of the OSI model).
IPS
The Intrusion Prevention System (IPS) is a more comprehensive security solution that concentrates on identifying and thwarting a variety of network-based threats. An IPS runs at many layers (mostly Layer 3 and Layer 4) and is intended to defend the entire network infrastructure, in contrast to a WAF, which focuses only on web applications.
NGFW
An advanced firewall known as a Next-Generation Firewall (NGFW) combines more complex security features like application-layer control, intrusion prevention, and deep packet inspection (DPI) with more conventional firewall features like packet filtering and network address translation. NGFWs provide more detailed traffic control and improved application usage visibility by combining the capabilities of firewalls and intrusion prevention systems.
RASP
A relatively newer solution called Runtime Application Self-Protection (RASP) focuses on securing apps from within by keeping an eye on and evaluating their actions while they are running. RASP offers continuous monitoring for risks like code injection and memory manipulation and is incorporated into a program or its runtime environment. RASP has the ability to stop harmful programs and prevent attacks when it detects a threat.
Firewall
A firewall is a type of security system that uses pre-established security rules to monitor and regulate all incoming and outgoing network traffic. It filters data packets to stop unwanted access and online dangers, operating as a barrier between a trusted internal network and an untrusted external network. In contrast, a Web Application Firewall (WAF) is made to safeguard web applications. In contrast to conventional firewalls, which safeguard the network, WAF handles application-layer threats like SQL injection and cross-site scripting (XSS).