Individual skill
subdomain-takeover
Subdomain takeover detection and exploitation playbook. Use when targets have dangling CNAME/NS/MX records pointing to deprovisioned cloud resources, expired third-party services, or unclaimed SaaS tenants that an attacker can register to serve content under the victim's domain.
skills/subdomain-takeover/SKILL.md
Source commit 6fbf0bc8d5c71830d62543a308d8744606c43d7c
What was checked
- Matches the observed repository HEAD
- Yes
- Scanner rules are current
- Yes
- Repository scan complete
- No
- Skill scan complete
- Yes
- Observed behavior
- Network or broad shell
- Last checked
- Nov 9, 2026
These are observations at the recorded commit, not a guarantee of safety. Review the source before running it.
Install this skill
Choose an agent in your Stack or copy a command below. Commands fetch the pinned commit and copy only this skill directory. Existing destinations are refused. Copying a command does not install anything.
An install command is unavailable: current rules, complete repository and skill scans, an eligible behavior level and a permitted license are required.
Repository context
- Repository stars (not skill ratings)
- 2,635
- Repository last updated
- Sep 13, 2026
- License
- MIT
Observed agent integration: No specific integration evidence. Standard SKILL.md installation does not imply verified compatibility.
- writing Derived category
Files and excerpt
File metadata and permitted, redacted excerpts come from the recorded scan. Source links are pinned to that commit.
Browse files
SKILL.mdcore · 10,857 bytes
Read excerpt
# SKILL: Subdomain Takeover — Detection & Exploitation Playbook
> **AI LOAD INSTRUCTION**: Covers CNAME/NS/MX takeover, per-provider fingerprint matching, claim procedures, and defensive monitoring. Base models often confuse "CNAME exists" with "takeover possible" — the key is whether the *resource behind the CNAME is unclaimed and claimable*.
## 0. RELATED ROUTING
- [ssrf-server-side-request-forgery](../ssrf-server-side-request-forgery/SKILL.md) when a subdomain takeover is used to bypass SSRF allowlists trusting `*.target.com`
- [cors-cross-origin-misconfiguration](../cors-cross-origin-misconfiguration/SKILL.md) when CORS trusts `*.target.com` — takeover → full cross-origin read
- [xss-cross-site-scripting](../xss-cross-site-scripting/SKILL.md) takeover gives you script execution under target origin (cookie theft, OAuth redirect abuse)
- [http-host-header-attacks](../http-host-header-attacks/SKILL.md) when Host routing leads to subdomain-scoped cache or auth issues
- [web-cache-deception](../web-cache-deception/SKILL.md) when a taken-over subdomain shares cache with the main domain
---
