Quick and Dirty Web Services Testing with Suds and Burp Suite | VerSprite Quick and Dirty Web Services Testing with Suds and Burp Suite | VerSprite

Quick and Dirty Web Services Testing with Suds and Burp Suite

Written By: Versprite

Cybersecurity Resources


This is a really simply example of using the Python Suds library to consume and inspect SOAP web services with integration into Burp Suite. I decided once upon a time that I didn’t think SoapUI was efficient for what I needed when it came testing web services and getting that data into Burp Suite, so I began searching for a simple Python library that could help me out. I will caveat that statement with, I always enjoy trying to write my own implementation of things, even if they aren’t the best, it helps with my overall objective -> Learning!

Getting Soapy

https://fedorahosted.org/suds/ – “Suds is a lightweight SOAP python client for consuming Web Services” So I stumbled upon Suds, which I must say is incredibly easy to use.  The best part about this library is that you can accomplish everything want from the console, which is always a plus.  Alright so in your Python console we want to import the Suds client and setup some logging so we can debug each web service request and response.

>>> from suds.client import Client
>>> import logging
>>> logging.basicConfig(level=logging.INFO)
>>> logging.getLogger('suds.client').setLevel(logging.DEBUG)


Now we need to setup some arguments for the suds client.  Things we will need – location of the web services descriptor file, and where Burp Suite is currently listening:


>>> url = "https://demowebservice/Auth.svc?wsdl"
>>> proxy = {}
>>> proxy['http'] = 'http://localhost:8080'
>>> proxy['https'] = 'https://localhost:8080'

Now the only thing we need to do is have our Suds client consume the web service with the arguments we setup and view the result.

>>> client = Client(url, proxy=proxy)
>>> print client
Suds ( https://fedorahosted.org/suds/ ) version: 0.4 GA build: R699-20100913
Service ( AuthenticationService ) tns="http://asp.net/ApplicationServices/v200"
    Prefixes (1)
       ns0 = "http://schemas.microsoft.com/2003/10/Serialization/"
    Ports (1):
          Methods (4):
             Login(xs:string username, xs:string password, xs:string customCredential, xs:boolean isPersistent, )
             ValidateUser(xs:string username, xs:string password, xs:string customCredential, )
          Types (3):


Alright, so all we have to do now is make sure Burp Suite is up and running, and call one of the methods provided to us in the web service.


>>> client.service.IsLoggedIn()
DEBUG:suds.client:sending to (https://demowebservice/Auth.svc)
<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:ns0="http://asp.net/ApplicationServices/v200" xmlns:ns1="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
DEBUG:suds.client:headers = {'SOAPAction': u'"http://asp.net/ApplicationServices/v200/AuthenticationService/IsLoggedIn"', 'Content-Type': 'text/xml; charset=utf-8'}
DEBUG:suds.client:http succeeded:
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"><s:Body><IsLoggedInResponse xmlns="http://asp.net/ApplicationServices/v200"><IsLoggedInResult>false</IsLoggedInResult></IsLoggedInResponse></s:Body></s:Envelope>

Burp Suite

Nothing fancy, but it gets the job done.  Enjoy!

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