subdomain-takeover

Analyze CNAME, NS, and MX records to detect subdomain takeover vulnerabilities.

Updated Aug 23, 2026
One-click install
npx skills add https://github.com/overtimepog/greyhatcc --skill subdomain-takeover
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: subdomain-takeover
Source: https://github.com/overtimepog/greyhatcc/tree/main/skills/subdomain-takeover
Command: npx skills add https://github.com/overtimepog/greyhatcc --skill subdomain-takeover

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) components.

What problem does it solve?

This Skill automates the detection of subdomain takeover vulnerabilities, which can be exploited to host malicious content or intercept sensitive data.

Core Features & Use Cases

  • Automated Detection: Identifies dangling CNAME, NS, and MX records pointing to cloud services that can be claimed.
  • Impact Analysis: Assesses the potential severity of a takeover based on how the subdomain is used (e.g., CSP, CORS, OAuth).
  • Second-Order Takeovers: Detects vulnerabilities where a trusted third-party domain has a claimable subdomain.
  • Use Case: A security team can use this skill to proactively scan their entire attack surface for subdomain takeover risks before attackers can exploit them.

Quick Start

Run the subdomain-takeover skill against the target domain example.com.

Frequently Asked Questions about subdomain-takeover

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

FAQPage Schema
How do I detect subdomain takeover vulnerabilities in dangling DNS records?

Detect subdomain takeover vulnerabilities by automating the analysis of CNAME, NS, and MX records for dangling pointers pointing to claimable cloud services. This process identifies exposed subdomains before attackers can exploit them to host malicious content.

What is a second-order subdomain takeover and how is it assessed?

A second-order subdomain takeover occurs when a trusted third-party domain has a claimable subdomain. It is assessed by examining trusted external domains for dangling pointers, extending vulnerability detection beyond the primary target's attack surface.

How do I analyze the impact of a subdomain takeover on CSP and CORS configurations?

Analyze the impact of a subdomain takeover on CSP and CORS configurations by evaluating the context in which the vulnerable subdomain is used. This impact analysis assesses potential severity based on sensitive data interception risks.

Can I scan my cloud security attack surface for dangling CNAME records automatically?

Yes, you can scan your cloud security attack surface for dangling CNAME records automatically. The automated detection evaluates various cloud services to identify and assess claimable resources across your external infrastructure.

Does subdomain takeover detection work for OAuth configurations?

Yes, subdomain takeover detection works for OAuth configurations by evaluating how the vulnerable subdomain is used. It assesses potential severity by checking if exploited dangling records can intercept sensitive OAuth authentication data.