WAF: protection every website needs
Web applications have become the core of modern business. They process orders, payments, user registrations, data storage and internal communication. The more valuable the service, the more often it becomes a target for attacks.
DDoS attacks are no longer the main threat to websites. Today, far more common are other hacking methods: SQL injections, XSS, API attacks and password brute force. These methods allow attackers to quietly access data or disrupt application logic and automation makes them scalable — bots can scan thousands of websites in minutes and find vulnerabilities.
What is WAF
WAF (Web Application Firewall) is a filter that sits between the user and the application. It analyzes HTTP(S) traffic and decides whether to allow or block a request.
Unlike a network firewall, which works with ports and IP addresses, WAF “understands” the structure of web requests. For example:
- SQL code is sent to a search field instead of text;
- hundreds of password attempts are sent per second to a login form.
Both cases are detected and blocked right at the entry point, before they ever reach the database or application.
What attacks does WAF prevent
WAF protects web applications from the most common threats frequently exploited by hackers. Among them:
- SQL injections — attempts to inject malicious code into database queries;
- XSS (cross-site scripting) — inserting scripts that steal user data or alter content;
- Brute force and session hijacking — mass password guessing and attempts to intercept user tokens;
- API attacks — overloading or exploiting weaknesses in data exchange interfaces;
- Application-level DDoS — flooding the site with requests aimed at logic rather than infrastructure;
- Exploitation of CMS and framework vulnerabilities — leveraging common flaws in popular systems and libraries.
This filtering helps stop hacking attempts before they reach the server and cause damage to data or application stability.
How WAF works
Protection is built from several components, each responsible for its own level of traffic analysis:
- Signature analysis detects matches with known attack patterns.
- Behavioral analysis identifies abnormal activity, such as multiple login attempts in a second.
- Machine learning recognizes application-specific traffic and reduces false positives.
- Real-time inspection blocks malicious requests before they reach the server.
With and without WAF: a clear comparison
| Situation | Without WAF | With WAF |
|---|---|---|
| SQL injection | Query reaches the database, data is stolen | Request is blocked at the entry |
| XSS attack | Script stealing cookies runs on the page | Suspicious code is filtered |
| Brute force | Unlimited login attempts | IP is blocked for suspicious activity |
| API attacks | Mass requests overload the service | Abnormal load is blocked at entry |
| Application-level DDoS | Site crashes, business loses revenue | Suspicious traffic is filtered out |
| CMS/API vulnerabilities | Exploits trigger before updates | Typical attacks are blocked even without a patch |
Last year’s statistics
What about the hard numbers? Is protection really that critical today? Let’s look at recent figures from Europe:
- According to ENISA (European Union Agency for Cybersecurity), API-related attacks in Europe grew by more than 250% in 2024 compared to the previous year.
- Over 2 billion security incidents were linked to web applications across the EU.
- The largest recorded attack in Europe reached peaks of more than 1.2 million requests per second — several times higher than the region’s previous records.
These numbers clearly show: web application protection is not “insurance just in case.” WAF is required to withstand attacks every single day.
Why it matters right now
Not long ago, many companies relied on Cloudflare, where CDN and WAF worked hand in hand, solving two tasks at once — speed and security. In Europe, this model has become the de facto standard.
Today, this combination is essential:
- CDN accelerates content delivery and reduces server load.
- WAF filters threats and protects applications.
For European businesses, the focus is shifting toward providers that combine global reach with compliance to local regulations such as GDPR, and that operate data centers within the EU. This ensures both performance and legal certainty while keeping critical applications secure and fast.
Common mistakes when implementing WAF
- Using default settings — without customization for the project, WAF is less effective.
- Believing WAF solves everything — it does not replace CMS updates or database protection.
- Ignoring logs — logs reveal which attacks are targeting your service.
- Not updating rules — outdated protection becomes ineffective quickly.
- Going straight to “combat mode” — it’s better to start in monitoring mode and fine-tune settings.
What businesses gain from WAF
- Reduced risks of data leaks and downtime.
- Compliance with requirements (e.g., PCI DSS).
- Savings on admin and developer resources.
- Integration with CDN or standalone use.
WAF is a fundamental element of web application security. It prevents the most common attacks, helps maintain compliance and sustains user trust.
Combined with CDN, it ensures a fast and resilient website. For the European market, this is especially important: businesses must meet both performance demands and strict compliance standards like GDPR, while still needing reliable protection and speed.
In the Serverspace control panel, you can enable both WAF and CDN in just a few minutes, covering both needs within a single infrastructure.
Serverspace is a cloud provider offering virtual infrastructure deployment on Linux and Windows platforms from anywhere in the world in under 1 minute. Tools like API, CLI and Terraform are available for seamless integration with client services.
