waf-path-bypass

Tests WAF edge blocks for path-normalization bypasses that expose origin-served sensitive routes.

7|4|Updated Jun 22, 2026
One-click install
npx skills add https://github.com/dbx0/skills --skill waf-path-bypass-dbx0
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: waf-path-bypass
Source: https://github.com/dbx0/skills/tree/main/skills/web-appsec/initial-access/waf-path-bypass
Command: npx skills add https://github.com/dbx0/skills --skill waf-path-bypass-dbx0

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? When a WAF or edge proxy blocks a sensitive path with a 403 or challenge page, the underlying origin server may still serve the same route under a normalized path variant, and manually probing these differences is error-prone and easy to do incompletely. ## Core Features & Use Cases - Edge vs. Origin Fingerprinting: Confirms whether a block is enforced at the WAF layer or the application layer by comparing response headers and body signatures. - Path Variant Testing: Systematically tries trailing slashes, doubled slashes, dot-segments, encoded slashes, and case variations that WAF string-match rules often miss but origin routers accept. - Severity Assessment: Provides a severity matrix based on what the bypass actually reaches, from cosmetic WAF gaps to unauthenticated admin endpoints. - Use Case: During an assessment, a Keycloak admin realm path returns a 403 from the edge. Use this Skill to test normalization variants, confirm the origin serves the realm's JWKS or config payload, and grade the finding correctly. ## Quick Start Test the blocked path /admin/realms/master on this target for WAF path-normalization bypasses and confirm whether the origin still serves the sensitive content.

Frequently Asked Questions about waf-path-bypass

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I bypass a WAF 403 block on a specific path?

Test path-normalization variants such as trailing slashes, doubled leading slashes, dot-segments, URL-encoded slashes, and case changes. WAF string-match rules often fail to normalize these while the origin router treats them as the same route.

How to tell if a 403 comes from the WAF or the application?

Compare response headers and body against a known application-level 403 on the same host. WAF blocks typically show vendor error pages or lack origin-specific headers, while application denials carry the app's normal markup and headers.

Is a 403 to 200 status change enough to confirm a WAF bypass?

No. Confirm the response body actually contains the sensitive content, such as a realm public key or admin markup, rather than a different error page. Reporting on status code alone is a common false positive.

What severity is a WAF path-normalization bypass?

Severity depends on what the bypass reaches. A cosmetic gap reaching the same login page is low, configuration or metadata disclosure is low to medium, and reaching functional endpoints with weak downstream authentication is high.

When does path normalization testing not work?

It fails when the WAF and origin normalize paths identically, or when the origin itself enforces the block. If one variant fails, try the other normalization forms before concluding the rule is correctly configured.