DNS Amplification Scanner - Metasploit


This page contains detailed information about how to use the auxiliary/scanner/dns/dns_amp metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.

Table Of Contents
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Module Overview

Name: DNS Amplification Scanner
Module: auxiliary/scanner/dns/dns_amp
Source code: modules/auxiliary/scanner/dns/dns_amp.rb
Disclosure date: -
Last modification time: 2017-08-26 21:01:10 +0000
Supported architecture(s): -
Supported platform(s): -
Target service / protocol: -
Target network port(s): 53
List of CVEs: CVE-2006-0987, CVE-2006-0988

This module can be used to discover DNS servers which expose recursive name lookups which can be used in an amplification attack against a third party.

Module Ranking and Traits

Module Ranking:

  • normal: The exploit is otherwise reliable, but depends on a specific version and can't (or doesn't) reliably autodetect. More information about ranking can be found here.

Basic Usage

This module is a scanner module, and is capable of testing against multiple hosts.

msf > use auxiliary/scanner/dns/dns_amp
msf auxiliary(dns_amp) > show options
    ... show and set options ...
msf auxiliary(dns_amp) > set RHOSTS ip-range
msf auxiliary(dns_amp) > exploit

Other examples of setting the RHOSTS option:

Example 1:

msf auxiliary(dns_amp) > set RHOSTS 192.168.1.3-192.168.1.200

Example 2:

msf auxiliary(dns_amp) > set RHOSTS 192.168.1.1/24

Example 3:

msf auxiliary(dns_amp) > set RHOSTS file:/tmp/ip_list.txt

Required Options

  • RHOSTS: The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'

Knowledge Base

Vulnerable Application

This module can be used to discover DNS servers which expose recursive name lookups which can be used in an amplification attack against a third party.

BIND 9.4.1-P1: source Ubuntu 7.10: Gutsy Gibbon

Verification Steps

  1. Start msfconsole
  2. Do: use modules/auxiliary/scanner/dns/dns_amp
  3. Do: set DOMAINNAME [domain]
  4. Do: set RHOST [ip]
  5. Do: run

Scenarios

A run on Ubuntu 7.10 (Gutsy Gibbon) and BIND 9.4.1-P1

  msf > use modules/auxiliary/scanner/dns/dns_amp
  msf auxiliary(scanner/dns/dns_amp) > set DOMAINNAME domain.com
    DOMAINNAME => domain.com
  msf auxiliary(scanner/dns/dns_amp) > set RHOSTS 192.168.10.254
    RHOSTS => 192.168.10.254
  msf auxiliary(scanner/dns/dns_amp) > run
    [*] Sending DNS probes to 192.168.10.254->192.168.10.254 (1 hosts)
    [*] Sending 70 bytes to each host using the IN ANY domain.com request
    [+] 192.168.10.254:53 - Response is 374 bytes [5.34x Amplification]
    [*] Scanned 1 of 1 hosts (100% complete)
    [*] Auxiliary module execution completed

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Msfconsole Usage

Here is how the scanner/dns/dns_amp auxiliary module looks in the msfconsole:

msf6 > use auxiliary/scanner/dns/dns_amp

msf6 auxiliary(scanner/dns/dns_amp) > show info

       Name: DNS Amplification Scanner
     Module: auxiliary/scanner/dns/dns_amp
    License: Metasploit Framework License (BSD)
       Rank: Normal

Provided by:
  xistence <[email protected]>

Check supported:
  No

Basic options:
  Name        Current Setting  Required  Description
  ----        ---------------  --------  -----------
  BATCHSIZE   256              yes       The number of hosts to probe in each set
  DOMAINNAME  isc.org          yes       Domain to use for the DNS request
  FILTER                       no        The filter string for capturing traffic
  INTERFACE                    no        The name of the interface
  PCAPFILE                     no        The name of the PCAP capture file to process
  QUERYTYPE   ANY              yes       Query type(A, NS, SOA, MX, TXT, AAAA, RRSIG, DNSKEY, ANY)
  RHOSTS                       yes       The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
  RPORT       53               yes       The target port (UDP)
  SNAPLEN     65535            yes       The number of bytes to capture
  THREADS     10               yes       The number of concurrent threads
  TIMEOUT     500              yes       The number of seconds to wait for new data

Description:
  This module can be used to discover DNS servers which expose 
  recursive name lookups which can be used in an amplification attack 
  against a third party.

References:
  https://nvd.nist.gov/vuln/detail/CVE-2006-0987
  https://nvd.nist.gov/vuln/detail/CVE-2006-0988

Module Options

This is a complete list of options available in the scanner/dns/dns_amp auxiliary module:

msf6 auxiliary(scanner/dns/dns_amp) > show options

Module options (auxiliary/scanner/dns/dns_amp):

   Name        Current Setting  Required  Description
   ----        ---------------  --------  -----------
   BATCHSIZE   256              yes       The number of hosts to probe in each set
   DOMAINNAME  isc.org          yes       Domain to use for the DNS request
   FILTER                       no        The filter string for capturing traffic
   INTERFACE                    no        The name of the interface
   PCAPFILE                     no        The name of the PCAP capture file to process
   QUERYTYPE   ANY              yes       Query type(A, NS, SOA, MX, TXT, AAAA, RRSIG, DNSKEY, ANY)
   RHOSTS                       yes       The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
   RPORT       53               yes       The target port (UDP)
   SNAPLEN     65535            yes       The number of bytes to capture
   THREADS     10               yes       The number of concurrent threads
   TIMEOUT     500              yes       The number of seconds to wait for new data

Advanced Options

Here is a complete list of advanced options supported by the scanner/dns/dns_amp auxiliary module:

msf6 auxiliary(scanner/dns/dns_amp) > show advanced

Module advanced options (auxiliary/scanner/dns/dns_amp):

   Name                   Current Setting  Required  Description
   ----                   ---------------  --------  -----------
   CHOST                                   no        The local client address
   CPORT                                   no        The local client port
   GATEWAY_PROBE_HOST     8.8.8.8          yes       Send a TTL=1 random UDP datagram to this host to discover the default gateway's MAC
   GATEWAY_PROBE_PORT                      no        The port on GATEWAY_PROBE_HOST to send a random UDP probe to (random if 0 or unset)
   NUM_REQUESTS           1                no        Number of requests to send
   SECRET                 1297303073       yes       A 32-bit cookie for probe requests.
   SRCIP                                   no        Use this source IP
   ScannerMaxResends      10               yes       The maximum times to resend a packet when out of buffers
   ScannerRecvInterval    30               yes       The maximum numbers of sends before entering the processing loop
   ScannerRecvQueueLimit  100              yes       The maximum queue size before breaking out of the processing loop
   ScannerRecvWindow      15               yes       The number of seconds to wait post-scan to catch leftover replies
   ShowProgress           true             yes       Display progress messages during a scan
   ShowProgressPercent    10               yes       The interval in percent that progress should be shown
   VERBOSE                false            no        Enable detailed status messages
   WORKSPACE                               no        Specify the workspace for this module

Auxiliary Actions

This is a list of all auxiliary actions that the scanner/dns/dns_amp module can do:

msf6 auxiliary(scanner/dns/dns_amp) > show actions

Auxiliary actions:

   Name  Description
   ----  -----------

Evasion Options

Here is the full list of possible evasion options supported by the scanner/dns/dns_amp auxiliary module in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):

msf6 auxiliary(scanner/dns/dns_amp) > show evasion

Module evasion options:

   Name  Current Setting  Required  Description
   ----  ---------------  --------  -----------

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Error Messages

This module may fail with the following error messages:

Error Messages

Check for the possible causes from the code snippets below found in the module source code. This can often times help in identifying the root cause of the problem.

Invalid query type!

Here is a relevant code snippet related to the "Invalid query type!" error message:

59:	    when 'DNSKEY'
60:	      querypacket="\x30"
61:	    when 'ANY'
62:	      querypacket="\xff"
63:	    else
64:	      print_error("Invalid query type!")
65:	      return
66:	    end
67:	
68:	    targdomainpacket = []
69:	    # Before every part of the domainname there should be the length of that part (instead of a ".")

<SHOST>:<RPORT> - Recursion not allowed

Here is a relevant code snippet related to the "<SHOST>:<RPORT> - Recursion not allowed" error message:

131:	          :refs => self.references)
132:	      end
133:	
134:	      # If these flags are set, we get a valid response but recursion is not available
135:	      if qr == "1" and ra == "0" and rcode == "0101"
136:	        print_status("#{shost}:#{datastore['RPORT']} - Recursion not allowed")
137:	        report_service(:host => shost, :port => datastore['RPORT'], :proto => 'udp', :name => "dns")
138:	      end
139:	    end
140:	  end
141:	end

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References

See Also

Check also the following modules related to this module:

Authors

  • xistence <xistence[at]0x90.nl>

Version

This page has been produced using Metasploit Framework version 6.2.1-dev. For more modules, visit the Metasploit Module Library.

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