Hunting Bugs with GAU and HTTPX: A Step-by-Step Guide

Bug bounty hunting is a thrilling field where security enthusiasts and professionals test their skills against live systems, seeking vulnerabilities that can be reported for rewards. In this guide, we'll explore how to use two powerful tools, GAU (Get All URLs) and HTTPX, to streamline your bug bounty hunting process.

Table of Contents

1. Introduction to Bug Bounty Hunting

2. Setting Up Your Environment

3. Gathering URLs with GAU

4. Probing URLs with HTTPX

5. Analyzing the Results

6. Tips for Effective Bug Bounty Hunting

7. Conclusion

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1. Introduction to Bug Bounty Hunting

Bug bounty programs allow individuals to discover and report security vulnerabilities in applications, websites, and other systems. Companies benefit by having a larger pool of testers, and hunters gain experience, recognition, and monetary rewards.

2. Setting Up Your Environment

Before diving into URL gathering and probing, you'll need to set up your environment. This guide assumes you have a basic understanding of command-line interfaces and have Python installed.

Install GAU

GAU is a powerful tool that extracts URLs from various sources, including Wayback Machine, Common Crawl, and URLScan.

go install github.com/lc/gau/v2/cmd/gau@latest

Install HTTPX

HTTPX is a fast and multi-purpose HTTP toolkit designed for security testing.

go install github.com/projectdiscovery/httpx/cmd/httpx@latest

3. Gathering URLs with GAU

GAU helps you gather URLs from multiple sources, providing a comprehensive list to work with.

Basic Usage

gau example.com

This command will output a list of URLs associated with example.com. You can redirect this output to a file for further processing:

gau example.com > urls.txt

Advanced Options

GAU offers several options to customize your URL gathering:

• -subs - Include subdomains in the search

• -o - Specify an output file

• -b - Specify sources to blacklist

Example:

gau -subs -o example_urls.txt example.com

4. Probing URLs with HTTPX

With your list of URLs, it's time to probe them using HTTPX. This tool helps you check the status of each URL, find alive hosts, and extract valuable information.

Basic Usage

cat urls.txt | httpx

This command reads URLs from urls.txt and probes them. HTTPX offers many options to customize its behavior:

• -status-code - Show HTTP status codes

• -content-length - Display content length

• -title - Display page title

• -tech-detect - Detect technologies used by the target

Example:

cat urls.txt | httpx -status-code -title -tech-detect -o probed_urls.txt

5. Analyzing the Results

Once you've gathered and probed URLs, the next step is analysis. Look for interesting endpoints, unusual HTTP status codes, or unexpected technologies. These could be indicators of potential vulnerabilities.

Filtering and Sorting

Use command-line tools like grep, awk, and sort to filter and sort the results. For example, to find all URLs with a 200 OK status:

grep "200" probed_urls.txt

6. Tips for Effective Bug Bounty Hunting

• Stay Updated: Follow security blogs, forums, and Twitter accounts to stay current with new vulnerabilities and techniques.

• Document Everything: Keep detailed notes of your findings, methodologies, and tools used.

• Respect Scope: Always adhere to the scope defined by the bug bounty program. Engaging out-of-scope targets can lead to legal consequences.

• Report Responsibly: Provide detailed, clear, and concise reports to program administrators. Include steps to reproduce, impact assessment, and possible mitigations.

7. Conclusion

Using GAU and HTTPX together can significantly enhance your bug bounty hunting efficiency. By automating URL gathering and probing, you can focus more on analysis and identifying potential vulnerabilities. Remember to always operate within the legal boundaries and ethical guidelines of the bug bounty programs you participate in.

Happy hunting!

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