Why the Number of WAF Rules Doesn’t Reflect Its Real Effectiveness

In the network security ecosystem, here is a common practice: WAF (Web Application Firewall) solutions that boast thousands of active rules. For an administrator evaluating products, that number may seem reassuring — more rules should theoretically mean more protection. But when you dig deeper, you quickly discover that many of those rules don’t apply to your infrastructure at all.

In several major solutions on the market, part of the rule catalog is dedicated to protecting highly specific technologies: particular PBX models, proprietary hardware, niche admin panels, or applications used by a tiny segment of the industry. If you don’t use those technologies — and most companies don’t — those rules don’t provide security. They simply add overhead to every inspection, increasing latency and operational noise.

To make things worse, in many solutions the WAF behaves like a black box the administrator cannot access.
You cannot see what each rule does, you cannot modify it, you cannot disable it, and you cannot add your own logic. You must rely on a set of policies you don’t control, performing checks you can’t always interpret, and consuming resources on every request.

This leads to a scenario many engineers will immediately recognize:

• A WAF with thousands of rules — and no visibility into how many actually apply to your environment.
• False positives that are hard to diagnose because you cannot inspect the internal logic of the rule.
• Difficulty understanding why a rule triggers or what pattern it is evaluating.

The Real Technical Problem Isn’t the Number of WAF Rules — It’s Their Relevance

When the inspection chain is full of irrelevant signatures, three things happen:

1. Processing costs increase.

Every irrelevant rule is still evaluated on each request, even if it will never trigger. This increases latency, consumes CPU unnecessarily, and adds load to the WAF pipeline without providing any real security. In high-traffic environments, this cumulative overhead can produce noticeable performance degradation.

2. Opacity escalates.

If you cannot see what each rule does or what pattern it evaluates, you cannot diagnose why a request is blocked or allowed. This lack of visibility prevents you from tuning your policy, obscures the WAF’s behaviour, and forces you to build your security strategy around the vendor’s assumptions rather than the needs of your architecture.

3. Control disappears.

If the security policy is a closed package, you cannot adapt it to your environment: you cannot fine-tune rules, disable those that don’t apply, or introduce your own logic. The only path to “improving” the system often ends up being additional proprietary modules, which add complexity but do not solve the underlying issue: the administrator has no real ability to design their own security posture.

This is why measuring a WAF by the number of rules it contains is an unreliable indicator. It says nothing about actual effectiveness and is often used more as a commercial argument than a technical benefit.

What Actually Matters in a Modern WAF

For an engineer evaluating a WAF seriously, the relevant criteria are very different:

✔ Cross-cutting rules, not signatures tied to applications you don’t use. HTTP standards validation, universal attack patterns (SQLi, XSS, LFI), anomalies and protocol violations.

✔ Full transparency. Visibility into each rule, its logic, its conditions, and its actions.

✔ Real control. The ability to enable, disable, modify, or add rules based on your architecture.

✔ A reduced but effective rule set. Less noise, fewer false positives, and lower CPU consumption.

✔ Clear diagnostics. Readable logs, traceability, and visibility into the decision flow.

This is the type of design that allows an administrator to trust the system — not because the catalog is huge, but because the policy is clean, understandable, and aligned with real-world risk.

A Practical Approach: Rules That Matter, Not Inflated Catalogs

At SKUDONET we know that system administrators don’t need thousands of WAF rules — they need rules that make sense for their stack.
That’s why our WAF is built around a set of more than 700 universal rules, focused on two areas that affect any web application:

• HTTP standard compliance: validating that requests are well-formed, that headers are consistent, and that the request flow follows the protocol.
• Cross-technology attack patterns: SQLi, XSS, LFI, RCE… vulnerabilities that can affect PHP, Python, Node.js or any modern framework in the same way.

Administrators have full access to the policy: they can inspect each rule, understand what it evaluates, modify it, create new ones, or disable those they don’t need. The goal is to give engineers total control over WAF behaviour so they can tailor it precisely to their environment.

This approach avoids unnecessary overhead, reduces latency, and results in a policy that is more coherent, more traceable, and significantly easier to audit.

“Thousands of Rules” Model vs. SKUDONET’s Approach

A WAF’s rule count tells you nothing about its actual security effectiveness — nor about its real coverage. Volume-based approaches usually translate into higher latency, less visibility, and less control.

It’s not about having more rules, it’s about having the right rules — and the ability to adjust them to what is truly happening inside your infrastructure.

If you want to validate a WAF where every rule is visible, adjustable and built for real relevance—not volume—you can request a 30-day full-featured trial of SKUDONET Enterprise Edition.