DNSTake

A fast tool to check missing hosted DNS zones that can lead to subdomain takeover.

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What is a DNS takeover?

DNS takeover vulnerabilities occur when a subdomain (subdomain.example.com) or domain has its authoritative nameserver set to a provider (e.g. AWS Route 53, Akamai, Microsoft Azure, etc.) but the hosted zone has been removed or deleted. Consequently, when making a request for DNS records the server responds with a SERVFAIL error. This allows an attacker to create the missing hosted zone on the service that was being used and thus control all DNS records for that (sub)domain.¹

Installation

from Binary

The ez way! You can download a pre-built binary from releases page, just unpack and run!

from Source

NOTE: Go 1.16+ compiler should be installed & configured!

Very quick & clean!

▶ go install github.com/pwnesia/dnstake/cmd/dnstake@latest

— or

Manual building executable from source code:

▶ git clone https://github.com/pwnesia/dnstake
▶ cd dnstake/cmd/dnstake
▶ go build .
▶ (sudo) mv dnstake /usr/local/bin

Usage

$ dnstake -h

  ·▄▄▄▄   ▐ ▄ .▄▄ ·▄▄▄▄▄ ▄▄▄· ▄ •▄ ▄▄▄ .
  ██▪ ██ •█▌▐█▐█ ▀.•██  ▐█ ▀█ █▌▄▌▪▀▄.▀·
  ▐█· ▐█▌▐█▐▐▌▄▀▀▀█▄▐█.▪▄█▀▀█ ▐▀▀▄·▐▀▀▪▄
  ██. ██ ██▐█▌▐█▄▪▐█▐█▌·▐█ ▪▐▌▐█.█▌▐█▄▄▌
  ▀▀▀▀▀• ▀▀ █▪ ▀▀▀▀ ▀▀▀  ▀  ▀ ·▀  ▀ ▀▀▀

        (c) pwnesia.org — v0.0.1

Usage:
  [stdin] | dnstake [options]
  dnstake -t HOSTNAME [options]

Options:
  -t, --target <HOST/FILE>    Define single target host/list to check
  -c, --concurrent <i>        Set the concurrency level (default: 25)
  -s, --silent                Suppress errors and/or clean output
  -o, --output <FILE>         Save vulnerable hosts to FILE
  -h, --help                  Display its help

Examples:
  dnstake -t (sub.)domain.tld
  dnstake -t hosts.txt
  dnstake -t hosts.txt -o ./dnstake.out
  cat hosts.txt | dnstake
  subfinder -silent -d domain.tld | dnstake

Workflow

DNSTake use RetryableDNS client library to send DNS queries. Initial engagement using Google & Cloudflare DNS as the resolver, then check & fingerprinting the nameservers of target host — if there is one, it will resolving the target host again with its nameserver IPs as resolver, if it gets weird DNS status response (other than NOERROR/NXDOMAIN), then it's vulnerable to be taken over. More or less like this in form of a diagram.

Currently supported DNS providers, see here.

References

• [1] https://github.com/indianajson/can-i-take-over-dns#what-is-a-dns-takeover
• https://0xpatrik.com/subdomain-takeover-ns/

License

DNSTake is distributed under MIT. See LICENSE.