Web Ring - Glamtariels Fountain Walkthrough

This is one of those challenges that was personally interesting, especially due to an Error I was making in the payload and and interesting challenge to implement XXE type attack. And this time it was definitely time for BurpSuite to be used (Free version is sufficient). As we progess through the doors upon completion of Borio Mine doors we are greeted and presented to look at an XXE type of challenge. When clicked at the fountain we are are redirected to the following URL https://glamtarielsfountain.com/

Difficulty Level 5/5

Where at the bottom of the page there are values Snack and Ticket. Which upon inspection of the JavaScript on the HTML page are nothing interesting and a rabbit hole to avoid with regards to cookie tampering or CSRF related attack.

It took some time for me to understand the different responses of the website and hit the reset button provided on the website accordingly.

 

Two Behaviours to note:

1.     If you see the following Response “Trying to TAMPER with Kringlecon’s……Please click him out of here”, then it means either you tampering with the cookie is not liked by the website or your cookie has expired and time to hit the rest button in either case. Check if the Snack and Ticket values are refreshed with new ones before you proceed

NOTE: image path starting with “static/images/Grinchun…..” in the response

2.     If you see the following Response “ Zoom, Zoom very Hasty, can’t do that yet!”. Then it means that you’ll have to wait until the 4 ring option appears and then try inject your XXE payload repeating one of those captured traffic in Burp.

Now in interacting with the website, we can drag and drop the icons from the right corner into the fountain or drop on the princess to collect more information. As we drag and drop items as per our hint, take notes on the Uppercase characters in from those messages. Example below

Where you can see as items get dropped on either of them, talking note of the Uppercase characters reveals more hints. (unsure what that eye was for, unsure if its an easter egg, was not interested to follow through :p)

Full list of uppercase characters

PATH, APP, TAMPER, SIMPLE FORMAT, RINGLIST, TYPE

 

And we near the end of the Drag of Drop game, we start seeing the rings icons show up. And the princess talking about silver rings being her favourite

Now lets capture one of the ring traffic for further steps of XXE injection. If you are beginner for using Burpsuite have pasted link in the troubleshoot section for Burp Academy that will help Burp and XXE related attacks

Based on the clues given through uppercase characters PATH, SIMPLE FORMAT (txt file ?) and RINGLIST (filename ?) lets try to retrieve file ringlist.txt from the previous identified image path with XML as an XXE payload to retrieve the file

 

Payload

<?xml version="1.0" encoding="UTF-8" ?>

 

<!DOCTYPE foo [ <!ENTITY xxe SYSTEM "file:///app/static/images/ringlist.txt"> ]>

<root>

  <imgDrop>&xxe;</imgDrop>

  <who>princess</who>

  <reqType>xml</reqType>

</root>

 

We also need to modify the conent-type parameter to XML with the intercepted request in Burp. Inorder to do this intercept one of the drag and drops request of the rings icon. Where in both request and reponse we will see JSON format, for XXE to be successful we should be able to change it to XML format with the request as we intercept. edit content-type to application/xml. Then add the XML payload instead of the JSON data in the request

Note: whitespaces can be an issue with the XML, so make sure the line breaks from your editor is all sorted out before you paste the payload in Burp

 

When queried for the ringlist, we were presented with the following image upon visiting the URL in the response

Text in the image: x_phial_pholder_2022, bluering.txt, redring.txt

 

Seems like redring.txt and bluering.txt are within the folder x_phial_pholder_2022, so if we modify our XXE payload as per the newly discovered folder path

The princess did mention heavily about her liking to Silverring , how about we force browse and look for silvering.txt via the XXE

We are presented with the following image upon visiting the URL in the response. 

Font in the image reads as goldring_to_be_deleted.txt, which leads us to inject our next payload grabbing this txt file.

Did not yield us the results we expected, but if we take a look at the response carefully, its hinting us something to do with the REQ and TYPE. So then if we move our injection into <reqType> tag guess that should work. So in our modified payload our external entity &xxe; will be moved into <reqType> Tag and the <imgDrop> tag will have default img1 value.

And if you navigate to the URL listed in the response, you hit the gold ring and the answer for the question is the URL of the this gold ring image. With that one of the toughest challenge is solved ;)

Troubleshoots

• Avoid VSRF related rabbit holes
• Avoid Cookie tampering related rabbit holes
• If you see the following response “Trying to TAMPER with Kringlecon’s……Please click him out of here”, hit Reset button
• If you see the following response “” , Wait until the silver ring or 4 rings show up, then start injecting the XXE payload. Or script yourself to the 4 rings stage if you hold a premium version of Burp
• With XXE Payload, careful with whitespace (this made to circle around this challenge for hours  https://portswigger.net/web-security, https://portswigger.net/web-security/xxe

Full Map

Web Ring Unlocked !