oxml_xxe
This tool is meant to help test XXE vulnerabilities in OXML document file formats. Currently supported:
- DOCX/XLSX/PPTX
- ODT/ODG/ODP/ODS
- SVG
- XML
- PDF (experimental)
- JPG (experimental)
- GIF (experimental)
BH USA 2015 Presentation:
Exploiting XXE in File Upload Functionality (Slides) (Recorded Webcast)
Blog Posts on the topic:
Exploiting XXE Vulnerabilities in OXML Documents - Part 1
Exploiting CVE-2016-4264 With OXML_XXE
Developer Build
OXML_XXE was re-written in Ruby using Sinatra, Bootstrap, and Haml. Installation should be easy:
-
You will need a copy of Ruby. RVM is suggested (https://rvm.io/rvm/install). ruby version 2.3.5 is supported.
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If you are running Ubuntu (or also verified on Kali) you will need a couple of dependencies:
apt-get install libsqlite3-dev libxslt-dev libxml2-dev zlib1g-dev gcc
To install RVM:
gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
\curl -sSL https://get.rvm.io | bash
Install Ruby 2.3.5 with RVM
rvm install 2.3.5
rvm use 2.3.5
Install dependencies and start the server:
cd oxml_xxe
gem install bundler
bundle install
ruby server.rb
Browse to http://127.0.0.1:4567 to get started.
Main Modes
There are two main modes:
Build a File
Build mode adds a DOCTYPE and inserts the XML Entity into the file of the users choice.
String Replace in File
String replacement mode goes through and looks for the symbol § in the document. The XML Entity ("&xxe;") replaces any instances of this symbol. Note, you can open the document in and insert § anywhere to have it replaced. The common use case would be a web application which reads in a xlsx and then prints the results to the screen. Exploiting the XXE it would be possible to have the contents printed to the screen.