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"Can I take over XYZ?" — a list of services and how to claim (sub)domains with dangling DNS records.


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Disclaimer ⚠️

The authors of this document take no responsibility for correctness. This project is merely here to help guide security researchers towards determining whether something is vulnerable or not, but does not guarantee accuracy. This project heavily relies on contributions from the public; therefore, proving that something is vulnerable is the security researcher and bug bounty program's sole discretion.

Furthermore, it is important to clarify that this project does not aim to identify or disclose bypasses to security measures implemented by various services. Instead, it is expected that such bypasses be reported directly to the affected service for appropriate action.

Finally, it is worth noting that some bug bounty programs may accept dangling DNS record reports without requiring proof of compromise.

What is a subdomain takeover?

Subdomain takeover vulnerabilities occur when a subdomain ( is pointing to a service (e.g. GitHub pages, Heroku, etc.) that has been removed or deleted. This allows an attacker to set up a page on the service that was being used and point their page to that subdomain. For example, if was pointing to a GitHub page and the user decided to delete their GitHub page, an attacker can now create a GitHub page, add a CNAME file containing, and claim

You can read up more about subdomain takeovers here:

Safely demonstrating a subdomain takeover

Based on personal experience, claiming the subdomain discreetly and serving a harmless file on a hidden page is usually enough to demonstrate the security vulnerability. Do not serve content on the index page. A good proof of concept could consist of an HTML comment served via a random path:

$ cat aelfjj1or81uegj9ea8z31zro.html
<!-- PoC by username -->

Please be advised that this depends on what bug bounty program you are targeting. When in doubt, please refer to the bug bounty program's security policy and/or request clarifications from the team behind the program.

How to use this project

I recommend searching for the name of the service you are targeting in the issues tab. That way you can see the on-going discussion and more detailed steps on how to claim the subdomain you are after.

How to contribute

You can submit new services here:

A list of services that can be checked (although check for duplicates against this list first) can be found here: #26.

All entries

Note: fingerprints.json is automatically updated based on the content of this table.

Column header definitions:

  • Engine: Name of service
  • Status: Whether the service is vulnerable
  • Verified by CI/CD: Whether automated fingerprint check is currently passing
  • Domains: Comma-separate domains (used for fingerprint auto-verification)
  • Fingerprint: Regex indicating vulnerable page (or NXDOMAIN, indicating non-existent DNS record)
  • Discussion: Link to issue on this repo for discussion
  • Documentation: Link to official documentation
Engine Status Verified by CI/CD Domains Fingerprint Discussion Documentation
AWS/Elastic Beanstalk Vulnerable 🟩 NXDOMAIN Issue #194
AWS/Load Balancer (ELB) Not vulnerable 🟥 NXDOMAIN Issue #137
AWS/S3 Vulnerable 🟩 The specified bucket does not exist Issue #36
Acquia Not vulnerable 🟥 Web Site Not Found Issue #103
Agile CRM Vulnerable 🟥 Sorry, this page is no longer available. Issue #145 Vulnerable 🟩 Ошибка 402. Сервис Айри.рф не оплачен Issue #104
Akamai Not vulnerable 🟥 Issue #13
Anima Vulnerable 🟩 The page you were looking for does not exist. Issue #126 Anima Documentation
Bitbucket Vulnerable 🟩 Repository not found Issue #97
Campaign Monitor Vulnerable 🟥 Trying to access your account? Issue #275 Support Page
Canny Vulnerable 🟥 Company Not Found There is no such company. Did you enter the right URL? Issue #114
Cargo Collective Vulnerable 🟥 404 Not Found Issue #152 Cargo Support Page
Cloudfront Not vulnerable 🟥 ViewerCertificateException Issue #29 Domain Security on Amazon CloudFront
Desk Not vulnerable 🟥 Please try again or try free for 14 days. Issue #9
Digital Ocean Vulnerable 🟥 Domain uses DO name servers with no records in DO.
Discourse Vulnerable 🟩 NXDOMAIN Issue #49 Hackerone
Dreamhost Not vulnerable 🟥 Site Not Found Well, this is awkward. The site you're looking for is not here. Issue #153 Issue #5
Fastly Not vulnerable 🟥 Fastly error: unknown domain: Issue #22
Feedpress Not vulnerable 🟥 The feed has not been found. Issue #80
Firebase Not vulnerable 🟥 Issue #128 Not vulnerable 🟥 404 Not Found Issue #101
Freshdesk Not vulnerable 🟥 We couldn't find servicedesk.victim.tld Maybe this is still fresh! You can claim it now at Issue #214 Freshdesk Support Page
Frontify Edge case 🟥 404 - Page Not Found Oops… looks like you got lost Issue #170
Gemfury Vulnerable 🟩 404: This page could not be found. Issue #154 Article
Getresponse Vulnerable 🟥 With GetResponse Landing Pages, lead generation has never been easier Issue #235
Ghost Vulnerable 🟥 Site unavailable\.&#124;Failed to resolve DNS path for this host Issue #89
Github Edge case 🟥 There isn't a GitHub Pages site here. Issue #37 Issue #68
Gitlab Not vulnerable 🟥 HackerOne #312118
Google Cloud Storage Not vulnerable 🟥 <?xml version='1.0' encoding='UTF-8'?><Error><Code>NoSuchBucket</Code><Message>The specified bucket does not exist.</Message></Error>
Google Sites Not vulnerable 🟥 The requested URL was not found on this server. That’s all we know. Issue #277 Google Support
HatenaBlog Vulnerable 🟩 404 Blog is not found
Help Juice Vulnerable 🟩 We could not find what you're looking for. Help Juice Support Page
Help Scout Vulnerable 🟩 No settings were found for this company: HelpScout Docs
Helprace Vulnerable 🟩 HTTP_STATUS=301 Issue #115
Heroku Edge case 🟥 No such app Issue #38
HubSpot Not vulnerable 🟥 This page isn't available Issue #59
Instapage Not vulnerable 🟥 Issue #73
Intercom Edge case 🟥 Uh oh. That page doesn't exist. Issue #69 Help center
JetBrains Vulnerable 🟥 is not a registered InCloud YouTrack PR #107 YouTrack InCloud Help Page
Key CDN Not vulnerable 🟥 Issue #112
Kinsta Not vulnerable 🟥 No Site For Domain Issue #48 kinsta-add-domain
Landingi Edge case 🟥 It looks like you’re lost... Issue #117
LaunchRock Vulnerable 🟥 HTTP_STATUS=500 Issue #74
Mailchimp Not vulnerable 🟥 We can't find that page It looks like you're trying to reach a page that was built by Mailchimp but is no longer active. Discussion #250
Mashery Edge case 🟥 Unrecognized domain Issue #14 HackerOne
Microsoft Azure Vulnerable 🟩,,,,,,,,,,,,,,,, NXDOMAIN Issue #35
Netlify Edge case 🟥 Not Found - Request ID: Issue #40
Ngrok Vulnerable 🟩 Tunnel .* not found Issue #92 Ngrok Documentation
Pantheon Vulnerable 🟥 404 error unknown site! Issue #24 Documentation Pantheon-Sub-takeover
Pingdom Vulnerable 🟥 Sorry, couldn't find the status page Issue #144 Support Page Vulnerable 🟥 The creators of this project are still working on making everything perfect! Issue #41
Readthedocs Vulnerable 🟥 The link you have followed or the URL that you entered does not exist. Issue #160
Sendgrid Not vulnerable 🟥
Shopify Edge case 🟥 Sorry, this shop is currently unavailable. Issue #32 Issue #46 Medium Article Vulnerable 🟥 Link does not exist Issue #260
SmartJobBoard Vulnerable 🟩 This job board website is either expired or its domain name is invalid. Issue #139 Support Page
Smartling Edge case 🟥 Domain is not configured Issue #67
Smugsmug Vulnerable 🟥 Issue #60
Squarespace Not vulnerable 🟥
Statuspage Not vulnerable 🟥 Status page pushed a DNS verification in order to prevent malicious takeovers what they mentioned in This Doc PR #105 PR #171 Statuspage documentation
Strikingly Vulnerable 🟩 PAGE NOT FOUND. Issue #58 Strikingly-Sub-takeover Vulnerable 🟩 project not found Issue #198 Surge Documentation
SurveySparrow Vulnerable 🟩 Account not found. Issue #281 Custom domain
Tilda Edge case 🟥 Please renew your subscription Issue #155 PR #20
Tumblr Edge case 🟥 Whatever you were looking for doesn't currently exist at this address Issue #240 Tumblr Custom Domains
Uberflip Vulnerable 🟩 The URL you've accessed does not provide a hub. Issue #150 Uberflip Documentation
Unbounce Not vulnerable 🟥 The requested URL was not found on this server. Issue #11
Uptimerobot Vulnerable 🟥 page not found Issue #45 Uptimerobot-Sub-takeover
UserVoice Not vulnerable 🟥 This UserVoice subdomain is currently available! Issue #163
Vercel Edge case 🟥 DEPLOYMENT_NOT_FOUND. Issue #183 Adding & Configuring a Custom Domain
WP Engine Not vulnerable 🟥
Webflow Edge case 🟥 The page you are looking for doesn't exist or has been moved. Issue #44 forum webflow
Wix Edge case 🟥 Looks Like This Domain Isn't Connected To A Website Yet! Issue #231
Wordpress Vulnerable 🟩 Do you want to register .* PR #176
Worksites Vulnerable 🟩, Hello! Sorry, but the website you&rsquo;re looking for doesn&rsquo;t exist. Issue #142
Zendesk Not vulnerable 🟥 Help Center Closed Issue #23 Zendesk Support