FFUF Claude Skill

Who this is for: Security professionals and developers who need to perform authorized web security testing, directory enumeration, and vulnerability discovery using the ffuf web fuzzer.

What This Skill Does

Integrates the ffuf (Fuzz Faster U Fool) web fuzzer for intelligent web security testing and reconnaissance tasks, enabling Claude to perform directory discovery, subdomain enumeration, and API endpoint finding.

Core Capabilities

Intelligent Fuzzing — Claude interprets testing goals and configures ffuf appropriately
Result Analysis — Automatic filtering and analysis of ffuf output
Safe Defaults — Includes rate limiting and sensible defaults to avoid aggressive testing
Wordlist Management — Helps select appropriate wordlists for different scenarios
Multiple Target Types — Directories, files, subdomains, API endpoints, parameters
Output Filtering — Filter by status code, size, words, lines for precise results

Usage

Directory Discovery

Fuzz the /api endpoint on example.com for hidden paths

Find common directories on https://example.com

Subdomain Enumeration

Enumerate subdomains for target.com

API Endpoint Discovery

Find API endpoints on api.example.com

File Discovery

Test for backup files on the /admin path

Find configuration files on the target

Example Output

User: "Find common directories on https://example.com"

Output:

MARKDOWN

## FFUF Scan Results

Target: https://example.com/FUZZ
Wordlist: /usr/share/wordlists/dirb/common.txt
Threads: 40

### Discovered Directories (Status 200)

| Path | Status | Size | Words |
|------|--------|------|-------|
| /admin | 200 | 1.2K | 45 |
| /api | 200 | 890B | 32 |
| /images | 200 | 2.1K | 12 |
| /static | 200 | 1.5K | 8 |

### Filtered Results
- Total requests: 4614
- Valid results: 4
- Filtered out: 4610 (by size/words)

Summary: 4 directories discovered with valid content.

Prerequisites

Install ffuf

macOS:

BASH

brew install ffuf

Linux:

BASH

go install github.com/ffuf/ffuf/v2@latest

Verify Installation:

BASH

ffuf --version

Installation

BASH

# Clone repository
git clone https://github.com/jthack/ffuf_claude_skill

# Copy to skills directory
mkdir -p ~/.claude/skills
cp -r ffuf_claude_skill/ffuf-skill ~/.claude/skills/

Safety & Ethics

IMPORTANT: This skill is for defensive security purposes only.

Do	Don't
Test systems you own	Test without permission
Respect rate limits	Cause service disruption
Follow responsible disclosure	Ignore applicable laws
Use for authorized testing	Use for malicious purposes

Unauthorized testing of systems is illegal and unethical.

Common Use Cases

Task	Example Command
Directory Fuzzing	`ffuf -u https://target.com/FUZZ -w wordlist.txt`
Subdomain Enum	`ffuf -u https://FUZZ.target.com -w subdomains.txt`
Parameter Fuzzing	`ffuf -u https://target.com/page?param=FUZZ -w params.txt`
Vhost Discovery	`ffuf -u https://target.com -H "Host: FUZZ" -w vhosts.txt`
Extension Fuzzing	`ffuf -u https://target.com/FUZZ -w wordlist.txt -e .php,.asp,.aspx`

Output Options

Flag	Description
`-json`	Output in JSON format for parsing
`-csv`	Output in CSV format
`-of html`	Output in HTML format
`-o output.txt`	Save output to file

Filtering Options

Flag	Description
`-fc 404`	Filter out status 404
`-fs 1234`	Filter by response size
`-fw 100`	Filter by word count
`-fl 50`	Filter by line count

Web application security assessments
Bug bounty reconnaissance
Penetration testing engagements
Security audit preparation
Attack surface discovery
API endpoint enumeration
Hidden resource discovery