Security Cipher
Home Blog About Us
Resources β–Ό
πŸ—ΊοΈ Penetration Testing Roadmap 🌐 Web Application Security Checklist πŸ€– OWASP Top 10 for LLM Applications 🧠 LLM AI Security Checklist πŸ› οΈ Security Tools 🎯 Penetration Testing Tricks πŸ“„ Secure Code Explain πŸ“– Vulnerability Explain ☁️ AWS Cloud Security Checklist
My Resume
Contact UsContact
← Security Tools View on GitHub

second-order

Scans for second-order subdomain takeover and crawls for interesting links and endpoints.

Second Order

Scans web applications for second-order subdomain takeover by crawling the app, and collecting URLs (and other data) that match certain rules, or respond in a certain way.

Installation

From binary

Download a prebuilt binary from the releases page and unzip it.

From source

Go version 1.17 is recommended.

go install -v github.com/mhmdiaa/second-order@latest

Docker

docker pull mhmdiaa/second-order

Command line options

  -target string
        Target URL
  -config string
        Configuration file (default "config.json")
  -depth int
        Depth to crawl (default 1)
  -header value
    	Header name and value separated by a colon 'Name: Value' (can be used more than once)
  -insecure
        Accept untrusted SSL/TLS certificates
  -output string
        Directory to save results in (default "output")
  -threads int
        Number of threads (default 10)

Configuration File

Example configuration files are in config

  • LogQueries: A map of tag-attribute queries that will be searched for in crawled pages. For example, "a": "href" means log every href attribute of every a tag.
  • LogNon200Queries: A map of tag-attribute queries that will be searched for in crawled pages, and logged only if they contain a valid URL that doesn't return a 200 status code.
  • LogInline: A list of tags whose inline content (between the opening and closing tags) will be logged, like title and script

Output

All results are saved in JSON files that specify what and where data was found

  • The results of LogQueries are saved in attributes.json
{
    "https://example.com/": {
        "input[name]": [
            "user",
            "id",
            "debug"
        ]
    }
}
  • The results of LogNon200Queries are saved in non-200-url-attributes.json
{
    "https://example.com/": {
        "script[src]": [
            "https://cdn.old_abandoned_domain.com/app.js",
        ]
    }
}
  • The results of LogInline are saved in inline.json
{
    "https://example.com/": {
        "title": [
            "Example - Home"
        ]
    },
      "https://example.com/login": {
        "title": [
            "Example - login"
        ]
    }
}

Usage Ideas

This is a list of tips and ideas (not necessarily related to second-order subdomain takeover) on what to use Second Order for.

  • Check for second-order subdomain takeover: takeover.json. (Duh!)
  • Collect inline and imported JS code: javascript.json.
  • Find where a target hosts static files cdn.json. (S3 buckets, anyone?)
  • Collect <input> names to build a tailored parameter bruteforcing wordlist: parameters.json.
  • Feel free to contribute more ideas!

References

https://shubs.io/high-frequency-security-bug-hunting-120-days-120-bugs/#secondorder

https://edoverflow.com/2017/broken-link-hijacking/

Press Escape to close the search panel.

Donate

Buy me a Coffee

Penetration Testing Services - Fiverr

Buy me a Coffee

Penetration Testing Services

penetration Testing Services

Web Application Security Quiz

Web Application Security Quiz

Daily Bug Bounty Writeups - Twitter

Daily Bug Bounty Writeups

Download our Latest Android Application

Guide for Penetration Testing

Daily Bug Bounty Writeups - Telegram

Daily Bug Bounty Writeups

Author

Piyush
Senior Product Security Engineer

Ethical Hacker || Penetration Tester || Gamer || Blogger || Application Security Engineer

READ ARTICLE

Donate

Buy me a Coffee

Recent Posts

  • Software Supply Chain Security in 2026: Packages, Pipelines, and Provenance
    Software Supply Chain Security in 2026: Packages, Pipelines, and Provenance
    August 10, 2026/
    0 Comments
  • I Ran Codex Security on a Shop API Lab: 14 Bugs, $1.64, Full Playbook
    I Ran Codex Security on a Shop API Lab: 14 Bugs, $1.64, Full Playbook
    August 3, 2026/
    0 Comments
  • How I Would Hack Your Startup in 24 Hours (Real-World Pentest Guide)
    How I Would Hack Your Startup in 24 Hours (Real-World Pentest Guide)
    July 27, 2026/
    0 Comments

Follow Us

SecurityCipher

Practical security guides, vulnerability deep-dives, and hands-on resources for bug bounty hunters and penetration testers.

Useful Links

  • Start Here
  • Cybersecurity Jobs
  • CVE Lookup
  • Bug Bounty Programs
  • Security Conferences
  • Payload Cheatsheets
  • Interview Prep
  • Report Templates
  • Blogs
  • About
  • Contact
  • RSS Feed

Recent Post

  • Software Supply Chain Security in 2026: Packages, Pipelines, and Provenance
  • I Ran Codex Security on a Shop API Lab: 14 Bugs, $1.64, Full Playbook
  • How I Would Hack Your Startup in 24 Hours (Real-World Pentest Guide)
Β© 2026 SecurityCipher. All rights reserved. Privacy Policies Β· Terms & Conditions