Why Do We Need WAF?

WAF or Web Application Firewall is considered a critical part of an effective security solution that fortifies website security and strengthens the overall security posture. In this article, an in-depth understanding of web app firewalls and their importance to overall security will be discussed in depth.

What is WAF?

At the airport security checkpoint, all passengers are frisked, and their baggage scanned as per security protocol. If there is anything suspicious or against the protocols, the passenger may be questioned, or baggage manually searched further or entry denied outrightly.

WAF, similar to the security checkpoint at an airport, is the first line of defense between the website and the internet. All web traffic and requests to the server are passed through the web app firewall, located on the edge before they reach the website/ server/ database. Bad/ malicious requests are filtered out, vulnerabilities are secured with virtual patches until fixed, and protection is provided against a diverse range of threats and bad actors by the web app firewall, functioning on the basis of the customs policies it is configured with.

Why is WAF Needed?

Effective Protection from Known Vulnerabilities and Threats

The level of risks faced by businesses from the fast-growing threat landscape is a function of the threat probability and its potential and is amplified by the vulnerabilities present in the application. Open gateways are provided by vulnerabilities for attackers to orchestrate attacks/ breaches. Websites are often snooped around by attackers on the lookout for such vulnerabilities.

The diverse set of known vulnerabilities such as SQL Injections, XSS, XXE, malware defacements, poor credentials, etc. are effectively protected against by WAF.

Additionally, it is equipped to block illegitimate traffic and allow only legitimate users to access the website, preventing vulnerabilities from being found and exploited.

To better understand how a WAF can safeguard against malicious attacks, consider these 8 methods the WAF uses to prevent attacks.

Identification And Protection Against Bad Bots

Given bot traffic makes up 40% of all internet traffic and that bad bots make up 60% of the bot traffic, businesses are faced with massive risks of bot attacks. An advanced, intelligent Web App Firewall, unlike network firewalls and anti-virus solutions, is well-equipped to effectively identify bad bot traffic using:

  • constantly updated signature pool
  • behavior analysis based on global, historical data
  • user-agent knowledge,
  • continuous traffic profiling and monitoring,
  • JavaScript No-Op (challenge-based approach) to force the user to prove they are not bots,
  • real-time intelligence

Upon identification, the web app firewall policies can be configured in the following ways to protect the website from bad bots.

  • Signature Blacklisting – Blocking of online entities based on identifiable, malicious signatures.
  • Geolocation Enforcement – Blocking website access to areas with no operations or delivery.
  • Session Limiting – Defining limits on session length, number of visits, and traffic volume to kill lengthy sessions, ensure session cookies are not saved, and minimize risks of bots leveraging security loopholes.
  • Blocking traffic from single IP addresses
  • Behavior monitoring to prevent brute-force attacks

Virtual Patching Coupled with Real Intelligence to Strengthen Security

Instantaneous virtual patches are applied by Web Application Firewalls when unprotected/ unfixed vulnerabilities are found on the website, giving developers ample time to fix and ensuring that these vulnerabilities are not leveraged by attackers.

More than just virtual patching, real intelligence is provided by advanced, new-age web app firewalls. Real intelligence on attack attempts, methods used, and so on can be converted into actionable insights to block specific users/ IP addresses and/or create custom rules based on attack behavior to shut them off.

Application Risk Specific Custom configuration

Continuous protection in the face of the fast-evolving threat landscape and the dynamic nature of websites/ applications is made possible by advanced Web App Firewalls that allow customization and configurability of policies. So, business logic flaws and zero-day threats can be effectively combated with WAF along with the diverse range of known vulnerabilities and bot attacks.

The achievement of compliance and regulatory requirements such as PCI-DSS is made possible by the high configurability of WAF. With a combination of whitelisting and blacklisting rules, access to the website can be effectively controlled by the business.

Protection against DDoS attacks

Multi-layered protection against DDoS attacks is provided by the best Web App Firewalls. These are equipped with globally dispersed, DDoS-resilient network architecture with built-in redundant resources that handle sudden traffic spikes and prevent Layer 3 and 4 attacks. Layer 7 attacks are prevented by the always-on protection, 24×7 availability, and expertise of certified security professionals of a managed, intelligent WAF.

Better Website Performance

When coupled with a Content Delivery Network (CDN), the website performance is enhanced without compromising on security. The speed of the website is accelerated as the content is cached and serviced from the closest data center, without accessing the web server every time; fewer computational resources are required to fulfill user requests.


In a nutshell, Web Application Firewalls are capable of immensely improving the security posture and performance of websites. It is a simple investment and seamless installation that can save millions of dollars for the business caused by data breaches and cyber-attacks.