FTP Bounce Port Scanner - Metasploit

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

Module Overview

Name: FTP Bounce Port Scanner
Module: auxiliary/scanner/portscan/ftpbounce
Source code: modules/auxiliary/scanner/portscan/ftpbounce.rb
Disclosure date: -
Last modification time: 2019-03-05 03:38:51 +0000
Supported architecture(s): -
Supported platform(s): -
Target service / protocol: ftp
Target network port(s): 21, 2121
List of CVEs: -

Enumerate TCP services via the FTP bounce PORT/LIST method.

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/portscan/ftpbounce
msf auxiliary(ftpbounce) > show options
    ... show and set options ...
msf auxiliary(ftpbounce) > set RHOSTS ip-range
msf auxiliary(ftpbounce) > exploit

Other examples of setting the RHOSTS option:

Example 1:

msf auxiliary(ftpbounce) > set RHOSTS 192.168.1.3-192.168.1.200 

Example 2:

msf auxiliary(ftpbounce) > set RHOSTS 192.168.1.1/24

Example 3:

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

Required Options

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

• BOUNCEHOST: FTP relay host

Knowledge Base

  msf > use modules/auxiliary/scanner/portscan/ftpbounce
  msf auxiliary(scanner/portscan/ftpbounce) > set BOUNCEHOST 172.17.0.2
    BOUNCEHOST => 172.17.0.2
  msf auxiliary(scanner/portscan/ftpbounce) > set PORTS 8080
    BOUNCEPORT => 8080
  msf auxiliary(scanner/portscan/ftpbounce) > set RHOSTS 172.17.0.4
    RHOSTS => 172.17.0.4
  msf auxiliary(scanner/portscan/ftpbounce) > set FTPUSER bob
    FTPUSER => bob
  msf auxiliary(scanner/portscan/ftpbounce) > set FTPPASS 12345
    FTPPASS => 12345
  msf auxiliary(scanner/portscan/ftpbounce) > run

    [+] 172.17.0.2:21 -  TCP OPEN 172.17.0.4:8080
    [*] 172.17.0.2:21 - Scanned 1 of 1 hosts (100% complete)
    [*] Auxiliary module execution completed

  root@ubuntu:~# nmap -p 8080 -v -b bob:[email protected] 172.17.0.4 -Pn

    Starting Nmap 7.60 ( https://nmap.org ) at 2019-11-25 20:34 UTC
    Resolved FTP bounce attack proxy to 172.17.0.2 (172.17.0.2).
    Initiating Parallel DNS resolution of 1 host. at 20:34
    Completed Parallel DNS resolution of 1 host. at 20:34, 0.00s elapsed
    Attempting connection to ftp://bob:[email protected]:21
    Connected:220---------- Welcome to Pure-FTPd [privsep] [TLS] ----------
    220-You are user number 1 of 5 allowed.
    220-Local time is now 20:34. Server port: 21.
    220-This is a private system - No anonymous login
    220-This server supports FXP transfers
    220-IPv6 connections are also welcome on this server.
    220 You will be disconnected after 15 minutes of inactivity.
    Login credentials accepted by FTP server!
    Initiating Bounce Scan at 20:34
    Discovered open port 8080/tcp on 172.17.0.4
    Completed Bounce Scan at 20:34, 0.00s elapsed (1 total ports)
    Nmap scan report for 172.17.0.4
    Host is up.

    PORT     STATE SERVICE
    8080/tcp open  http-proxy

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Msfconsole Usage

Here is how the scanner/portscan/ftpbounce auxiliary module looks in the msfconsole:

msf6 > use auxiliary/scanner/portscan/ftpbounce

msf6 auxiliary(scanner/portscan/ftpbounce) > show info

       Name: FTP Bounce Port Scanner
     Module: auxiliary/scanner/portscan/ftpbounce
    License: Metasploit Framework License (BSD)
       Rank: Normal

Provided by:
  kris katterjohn <[email protected]>

Check supported:
  No

Basic options:
  Name        Current Setting      Required  Description
  ----        ---------------      --------  -----------
  BOUNCEHOST                       yes       FTP relay host
  BOUNCEPORT  21                   yes       FTP relay port
  DELAY       0                    yes       The delay between connections, per thread, in milliseconds
  FTPPASS     [email protected]  no        The password for the specified username
  FTPUSER     anonymous            no        The username to authenticate as
  JITTER      0                    yes       The delay jitter factor (maximum value by which to +/- DELAY) in milliseconds.
  PORTS       1-10000              yes       Ports to scan (e.g. 22-25,80,110-900)
  RHOSTS                           yes       The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
  THREADS     1                    yes       The number of concurrent threads (max one per host)

Description:
  Enumerate TCP services via the FTP bounce PORT/LIST method.

Module Options

This is a complete list of options available in the scanner/portscan/ftpbounce auxiliary module:

msf6 auxiliary(scanner/portscan/ftpbounce) > show options

Module options (auxiliary/scanner/portscan/ftpbounce):

   Name        Current Setting      Required  Description
   ----        ---------------      --------  -----------
   BOUNCEHOST                       yes       FTP relay host
   BOUNCEPORT  21                   yes       FTP relay port
   DELAY       0                    yes       The delay between connections, per thread, in milliseconds
   FTPPASS     [email protected]  no        The password for the specified username
   FTPUSER     anonymous            no        The username to authenticate as
   JITTER      0                    yes       The delay jitter factor (maximum value by which to +/- DELAY) in milliseconds.
   PORTS       1-10000              yes       Ports to scan (e.g. 22-25,80,110-900)
   RHOSTS                           yes       The target host(s), range CIDR identifier, or hosts file with syntax 'file:<path>'
   THREADS     1                    yes       The number of concurrent threads (max one per host)

Advanced Options

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

msf6 auxiliary(scanner/portscan/ftpbounce) > show advanced

Module advanced options (auxiliary/scanner/portscan/ftpbounce):

   Name                 Current Setting  Required  Description
   ----                 ---------------  --------  -----------
   CHOST                                 no        The local client address
   CPORT                                 no        The local client port
   ConnectTimeout       10               yes       Maximum number of seconds to establish a TCP connection
   FTPDEBUG             false            no        Whether or not to print verbose debug statements
   FTPTimeout           16               yes       The number of seconds to wait for a reply from an FTP command
   PassiveMode          false            no        Set true for extended passive (EPSV) ftp mode.
   Proxies                               no        A proxy chain of format type:host:port[,type:host:port][...]
   SSL                  false            no        Negotiate SSL/TLS for outgoing connections
   SSLCipher                             no        String for SSL cipher - "DHE-RSA-AES256-SHA" or "ADH"
   SSLVerifyMode        PEER             no        SSL verification method (Accepted: CLIENT_ONCE, FAIL_IF_NO_PEER_CERT, NONE, PEER)
   SSLVersion           Auto             yes       Specify the version of SSL/TLS to be used (Auto, TLS and SSL23 are auto-negotiate) (Accepted: Auto, TLS, SSL23, SSL3, TLS1, TLS1.1, TLS1.2)
   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/portscan/ftpbounce module can do:

msf6 auxiliary(scanner/portscan/ftpbounce) > show actions

Auxiliary actions:

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

Evasion Options

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

msf6 auxiliary(scanner/portscan/ftpbounce) > show evasion

Module evasion options:

   Name                Current Setting  Required  Description
   ----                ---------------  --------  -----------
   TCP::max_send_size  0                no        Maxiumum tcp segment size.  (0 = disable)
   TCP::send_delay     0                no        Delays inserted before every send.  (0 = disable)

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Error Messages

This module may fail with the following 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.

PORTS

Here is a relevant code snippet related to the "PORTS" error message:

46:	  end
47:	
48:	  def run_host(ip)
49:	    ports = Rex::Socket.portspec_crack(datastore['PORTS'])
50:	    if ports.empty?
51:	      raise Msf::OptionValidateError.new(['PORTS'])
52:	    end
53:	
54:	    jitter_value = datastore['JITTER'].to_i
55:	    if jitter_value < 0
56:	      raise Msf::OptionValidateError.new(['JITTER'])

JITTER

Here is a relevant code snippet related to the "JITTER" error message:

51:	      raise Msf::OptionValidateError.new(['PORTS'])
52:	    end
53:	
54:	    jitter_value = datastore['JITTER'].to_i
55:	    if jitter_value < 0
56:	      raise Msf::OptionValidateError.new(['JITTER'])
57:	    end
58:	
59:	    delay_value = datastore['DELAY'].to_i
60:	    if delay_value < 0
61:	      raise Msf::OptionValidateError.new(['DELAY'])

DELAY

Here is a relevant code snippet related to the "DELAY" error message:

56:	      raise Msf::OptionValidateError.new(['JITTER'])
57:	    end
58:	
59:	    delay_value = datastore['DELAY'].to_i
60:	    if delay_value < 0
61:	      raise Msf::OptionValidateError.new(['DELAY'])
62:	    end
63:	
64:	    return if not connect_login
65:	
66:	    ports.each do |port|

Unknown error

Here is a relevant code snippet related to the "Unknown error" error message:

91:	
92:	        if resp =~ /^[12]/
93:	          print_good(" TCP OPEN #{ip}:#{port}")
94:	          report_service(:host => ip, :port => port)
95:	        end
96:	      rescue ::Exception
97:	        print_error("Unknown error: #{$!}")
98:	      end
99:	    end
100:	  end
101:	end

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Related Pull Requests

• #11523 Merged Pull Request: MSF5: Remove unneeded RHOST deregister in scanners
• #8716 Merged Pull Request: Print_Status -> Print_Good (And OCD bits 'n bobs)
• #8338 Merged Pull Request: Fix msf/core and self.class msftidy warnings
• #6655 Merged Pull Request: use MetasploitModule as a class name
• #6648 Merged Pull Request: Change metasploit class names
• #6317 Merged Pull Request: Add capability for delays (+/- jitter) to all auxiliary scanner modules & implement in portscan modules
• #3235 Merged Pull Request: First little bit at Bug 8498
• #2779 Merged Pull Request: Raise Msf::OptionValidateError when the PORTS option is invalid
• #2525 Merged Pull Request: Change module boilerplate
• #1228 Merged Pull Request: MSFTIDY cleanup #1 - auxiliary

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See Also

Check also the following modules related to this module:

• auxiliary/scanner/natpmp/natpmp_portscan
• auxiliary/scanner/portscan/ack
• auxiliary/scanner/portscan/syn
• auxiliary/scanner/portscan/tcp
• auxiliary/scanner/portscan/xmas
• auxiliary/scanner/sap/sap_router_portscanner
• auxiliary/scanner/http/frontpage_credential_dump

Authors

kris katterjohn

Version

This page has been produced using Metasploit Framework version 6.1.27-dev. For more modules, visit the Metasploit Module Library.

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