Hi!
In the course of a recent penetration test, we came across an Image validation vulnerability in Django when using the Python-Imaging-Library (PIL) which we want to explain in this post.
Everybody who doesn’t know what Django and/or the PIL is:
Django is a framework to create web applications with Python (comparable to Rails or Zend). The PIL is a powerful standard python library which provides a toolset to modify, display and verify images of many different formats.