How to Improve Cloud Security With a Web Application Firewall (WAF)?

Updated Dec 19, 2022 • 10 min read

A cloud web application firewall (WAF) is a security solution that protects web applications from attack.

It sits between the Internet and the web application, intercepting traffic to and from the application. A cloud-based WAF provides increased security, improved performance, simplified management, and lower costs compared to an on-premises solution.

If you're looking for a cloud WAF solution, there are a few things to consider:

First, what type of traffic do you want to protect? Incoming or outgoing?
Second, what level of protection do you need? Basic, intermediate, or advanced?
Third, what features are important to you?

Some solutions offer more than just WAF protection, such as DDoS protection and custom security rules. Others include features like rate limiting and bot management. For an additional cost, you can purchase a managed solution and have a designated security consultant monitor your service.

Finally, what's your budget? Cloud WAF products can range from free to thousands of dollars per month. Shop around and compare features to find the best fit for your needs.

What are the benefits of using a cloud WAF?

There are several benefits to using a cloud-based WAF:

Increased app security: By sitting between the Internet and the web application, a WAF can protect against a wide range of attacks.
Improved performance: A WAF offloads security processing from the web application server, freeing up resources and improving performance.
Simplified management: A cloud-based WAF takes care of all the complex security processing, making it easy to manage, even for non-technical users.
Lower costs: A cloud-based WAF can be more affordable than an on-premises solution since you don't need to purchase and maintain hardware and software.

What does a WAF protect against?

A WAF can protect against a wide range of attacks, including:

SQL injection: Malicious code is injected into an SQL database to extract data or damage the database.
Cross-site scripting (XSS): Malicious code is injected into a web page to hijack user sessions or steal information.
Application denial of service (DoS): A DoS attack prevents legitimate users from accessing a web application by flooding it with requests.
Distributed denial of service (DDoS): A DDoS attack is similar to a DoS attack but comes from multiple computers, making it more difficult to block.
Malware: Malicious software, such as viruses and worms, can infect a web application and damage it or steal sensitive data.

A WAF can also protect against more sophisticated attacks, such as polymorphic and zero-day attacks.

How does a cloud WAF work?

A cloud-based WAF works by protecting web applications from attacks that exploit vulnerabilities in the application layer. The WAF resides between the Internet and the web application, intercepting all traffic to and from the application.

When a user attempts to access a protected web application, the WAF will first check to see if the user is allowed to access the site. If the user is not on the whitelist, the request will be blocked. If the user is on the whitelist, the WAF will then check to see if there are any malicious payloads in the request. If any are found, the request will be blocked. Otherwise, they will be allowed through to the web application.

The WAF will also monitor for any suspicious or malicious activity and block requests that meet certain criteria. For example, a WAF may block all requests from a particular IP address if it detects a high number of requests coming from that address in a short period of time.

Cloud WAF controls and capabilities

A cloud WAF provides security controls and capabilities that are similar to an on-premises WAF. These include:

Traffic filtering: The WAF can filter traffic based on parameters such as source IP address, URL, and HTTP headers.
Security rules: Security rules define what traffic should be allowed or blocked. Rules can be created manually or generated automatically based on malicious activity detected by the WAF.
Rate limiting: Rate limiting can be used to prevent DoS and DDoS attacks by limiting the number of requests a user can make in a given period of time.
Bot management: Bot management features can block automated traffic, such as bots and web crawlers, from accessing a web application.
Web application firewalling (WAF): A WAF engine protects against attacks that exploit vulnerabilities in web applications, such as SQL injection and cross-site scripting (XSS). The most popular WAF rulesets are based on the OWASP Core Rule Set (CRS) and ModSecurity Rules.
DDoS protection: DDoS protection defends against distributed denial of service (DDoS) attacks by identifying and blocking malicious traffic before it reaches the web application server.
SSL/TLS encryption: SSL/TLS encryption can be used to encrypt traffic to and from the web application. This protects data in transit from being intercepted and read by attackers.

How to implement a cloud WAF?

Implementing a cloud-based WAF is typically a simpler and more affordable process than setting up an on-premises solution. To get started, you'll need to sign up for a WAF service and configure it to work with your web application.

The specifics will vary depending on which WAF service you use, but the general steps are as follows:

Choose a WAF service: There are many different WAF services available, so take some time to compare features and prices before choosing one.
Set up the WAF: This usually involves creating an account and adding your web application.
Configure the WAF: Once the WAF is set up, you'll need to configure it to work with your web application. This includes specifying which traffic to allow or block and setting up security rules.
Test the WAF: Before going live with the WAF, it's important to test it to make sure it's working as expected. Send some test traffic to the WAF and check to see that it's being handled properly.

Which cloud WAF is best for you?

The best cloud WAF for you will depend on your specific needs and requirements. If you need a basic level of protection, a free solution like Cloudflare may be sufficient. If you need advanced protection, an all-in-one solution like Imperva Incapsula or Akamai Kona Site Defender may be a better choice. Ultimately, it's important to compare features and prices to find the best fit for your organization.

Now that you know what to look for in a cloud WAF solution, it's time to compare some of the top options. Here are some of the best, based on customer reviews and expert opinions:

Cloudflare

Cloudflare is a popular choice for those looking for a free solution. It offers basic WAF protection against common attacks, such as SQL injection and cross-site scripting (XSS). However, it doesn't offer more advanced features, such as bot management or rate limiting.

F5 Silverline WAF

F5 Silverline WAF is a good choice for those who need advanced protection. It offers all the standard features, plus DDoS protection and web application firewalling. It's one of the more expensive options, starting at $2,500 per month.

Incapsula Enterprise WAF

Incapsula Enterprise WAF is another good choice for advanced protection. It offers all the standard features, plus DDoS protection and web application firewalling. It's also one of the more expensive options, starting at $2,000 per month. However, it does include a 14-day free trial.

AWS WAF

AWS WAF is a good choice for those looking for a cloud WAF solution that integrates with other Amazon Web Services (AWS) products. It offers all the standard features, plus DDoS protection and web application firewalling. Prices start at $5 per month.

Azure WAF

Azure WAF is a good choice for those looking for a cloud WAF solution that integrates with other Microsoft Azure services. It offers all the standard features, plus DDoS protection and web application firewalling. Prices start at $5 per month.

Palo Alto WildFire

WildFire is a good choice for those looking for advanced protection. It offers all the standard features, plus DDoS protection and web application firewalling. Prices start at $3,500 per month.

Sucuri CloudProxy

Sucuri’s WAF is a good choice for those looking for an affordable solution. It offers all the standard features, plus DDoS protection and web application firewalling. Prices start at $200 per month.

Alert Logic Cloud Defender

Alert Logic Cloud Defender is a good choice for those looking for an all-in-one solution. It offers all the standard features, plus DDoS protection and web application firewalling. Prices start at $500 per month.

Imperva Incapsula

Imperva Incapsula is a good choice for those looking for an all-in-one solution. It offers all the standard features, plus DDoS protection and web application firewalling. Prices start at $2,000 per month.

Akamai Kona Site Defender

Akamai KSD is a good choice for those looking for an all-in-one solution. It offers all the standard features, plus DDoS protection and web application firewalling. Prices start at $1,500 per month.

Securing web applications with a cloud WAF

There are many benefits to using a cloud-based WAF, including increased security, improved performance, simplified management, and lower costs.

When choosing a cloud WAF solution, it's important to consider your needs and requirements. Some solutions offer more features than others, so be sure to compare features and prices before making a decision.