Balancing Security and Performance in the WAF

If you’re trying to decide which WAF (web application firewall) to use to improve performance and security, you likely have found some conflicting information. While some camps swear by the network-based WAF, for example, for its speed, others find it too expensive and time-consuming to set up and maintain. Cloud-based WAFs are available, but they come with monthly fees that other types do not.

Nonetheless, if WAF cyber security is the right choice for your organization, you’ll want to find the best WAF for you. Find one that best balances comprehensive security for your web applications without causing the performance of those applications to suffer. In short, keep customer data secure without inconveniencing them. With the right WAF, this is very doable.

The Role of the WAF

A web application firewall, more easily known as a WAF, acts as a first line of defense around your network and endpoints. Essentially, it serves a similar purpose as a traditional firewall, but it is works on HTTP requests rather than simply filtering traffic inbound to your network. WAFs protect your web applications, which are typically cloud-based assets.

Built to withstand a myriad of ever-evolving threats, WAFs often have some additional security features compared to traditional firewalls. However, their fundamental purpose is the same: block incoming, malicious traffic and prevent unauthorized data access and exfiltration.

Using rules and activity patterns, the WAF detects unauthorized access requests and blocks them. Malicious bots and bad actors generally behave much differently than legitimate users, and WAFs can detect these differences through testing and rules. These rules derive from known OWASP vulnerabilities. Once malicious activity is detected, the WAF blocks it, preventing access to your network and data.

Importance of Balancing Security and Performance

WAFs distinguish between normal and malicious activity, which is essential for your organization’s continued success. Blocking too much traffic risks blocking legitimate customers from accessing your application or their own data, which will have negative impacts on your business. Denied access will likely frustrate your customers and can damage your ability to generate revenue.

Beyond the customer experience, security and performance need to balance out. A WAF that provides more in-depth inspection offers better security. Bots are becoming increasingly sophisticated, so the most basic WAFs may catch some malicious requests. However, implementing a WAF with deeper inspection capabilities and adaptability may cost you some application performance.

Because WAFs screen incoming requests and respond, they require some server resources. More complex WAFs require more of those resources. In some cases, they can significantly increase processing time and loading issues. Your application serves as a point of contact for your customers, so it’s important to balance the need for high security and high performance.

The type of WAF you choose will contribute to this balance. Typically, organizations have a choice between three options:

• Network-based

This type keeps response times low. Because it is installed on local devices, it can communicate with your servers more quickly than WAFs based elsewhere. This means higher security is achievable, but it comes at a higher cost due to infrastructure requirements.

• Host-based

A host-based WAF lives inside of your application, which is great for tailoring the WAF to suit the application it protects. However, it can make the application clunky. The WAF is not a negligible user of server resources, and that shows when it’s built into the web app. On the upside, it’s less expensive than a network-based WAF. Just be aware you’re still paying for some infrastructure and extra security around your host server.

• Cloud-based

Rather than hosting and managing your WAF yourself, a cloud-based WAF operates as a paid service. Another company provides the WAF for your applications. Therefore, you are not responsible for infrastructure or maintenance. Since you’re paying monthly or annually for the service, however, make sure the WAF you choose suits your application and has sufficient customization options.

Optimizing the WAF

To effectively balance security and performance, you’ll need to optimize your WAF use. The easiest way to start is by implementing the right solution. For many organizations, this is a cloud-based, fully integrated WAF. Ideally, your WAF will be highly customizable so that you can configure it using the risk profile of your web app.

The WAF you choose should include the following features, among others:

• Adaptability and customization

Some WAFs use machine learning to automate the process of adjusting rules. Because these rules are the basis for allowing or blocking traffic, real-time adjustments are beneficial. However, you should be able to manually update rules yourself in addition to automated tweaks. Take time to tailor your WAF to your application’s specific needs and vulnerabilities.

• Traffic pattern analysis

Some WAFs have begun incorporating AI, which has been a game-changer for blocking suspicious activity without blocking unusual but legitimate activity. All WAFs are generally effective at handling known attack patterns, but AI-powered analysis can help your WAF detect some unknown attack patterns, something WAFs historically were not able to do well.

• DDoS protection

Cloud-based WAF allows you to transfer traffic. Therefore, your application won’t get bogged down with bot requests as it would without this support.

• CDNs

Content delivery networks (CDNs) help balance security with performance by decreasing load time for your application. This is one of the things that gives the cloud-based WAF an edge.

Once you have found a WAF that will work for you, it’s important to focus on customization before deployment. Consider performing a risk assessment on your web app so that you know all your vulnerabilities. This will inform your strategy going forward, ensuring you optimize rules and responses for your needs.