What Does A Web Application Firewall Do?

Every new web application involving the exchange of data between servers increases your exposure to cybersecurity threats. A web application firewall (WAF) can help.

What does a web application firewall do? It protects you against potential security hazards. Unlike a classic firewall working at the network level, a WAF protects you at the application level.

Cybersecurity threats WAFs protect against include:

• Malicious bots. A WAF maintains an ever-growing list of bad bots that, once flagged, can no longer compromise a site’s data.
• Damaging uploads. A WAF may provide tools to blacklist known bad actors—or block connections based on suspicious upload or modification patterns.
• Distributed denial of service. Sometimes hackers dispatch an army of bots to paralyze your app. WAFs can combat this.

More on what does a web application firewall do:

WAFs also protect your technology against unwanted SQL injections, cross-site scripting, and the Open Web Application Security Project (OWASP) top 10.

How does a web application firewall work?

WAFs come in several formats: hardware, software, cloud-based, or any combination thereof. How a web application firewall works is by operating a set of policies—instructions, essentially—that analyze inbound traffic and determine whether it’s legitimate or should be blocked.

WAFs recognize suspicious data sent via HTTP/HTTPS—and blocks that data. These policies are typically set up in one of three different models exemplifying how does a web application firewall work:

• Whitelisting:
  • A whitelisted IP can bypass security rules because it’s considered a trusted source. This means that if the firewall would block an action normally, because the source is whitelisted, the action is allowed.
• Blacklisting:
  • A resource that is blacklisted is blocked from making a connection to your site. For example, when a bot is blacklisted it can’t crawl or review any content on the website due to the blacklisting rules.
• Hybrid
  • A combination of whitelisting and blacklisting

The WAF scans your web applicants to filter out any potential threats or attacks—blocking access to the vulnerability. From there, the vulnerability still needs to be addressed directly. In a nutshell, this is how a web application firewall works.

To talk with one of our cybersecurity experts about web application firewalls or other SiteLock website security products, get in touch today.