mirror of
https://github.com/django/django.git
synced 2024-11-25 07:59:34 +01:00
69 lines
3.3 KiB
Plaintext
69 lines
3.3 KiB
Plaintext
===========================
|
|
Django 1.4.18 release notes
|
|
===========================
|
|
|
|
*January 13, 2015*
|
|
|
|
Django 1.4.18 fixes several security issues in 1.4.17 as well as a regression
|
|
on Python 2.5 in the 1.4.17 release.
|
|
|
|
WSGI header spoofing via underscore/dash conflation
|
|
===================================================
|
|
|
|
When HTTP headers are placed into the WSGI environ, they are normalized by
|
|
converting to uppercase, converting all dashes to underscores, and prepending
|
|
``HTTP_``. For instance, a header ``X-Auth-User`` would become
|
|
``HTTP_X_AUTH_USER`` in the WSGI environ (and thus also in Django's
|
|
``request.META`` dictionary).
|
|
|
|
Unfortunately, this means that the WSGI environ cannot distinguish between
|
|
headers containing dashes and headers containing underscores: ``X-Auth-User``
|
|
and ``X-Auth_User`` both become ``HTTP_X_AUTH_USER``. This means that if a
|
|
header is used in a security-sensitive way (for instance, passing
|
|
authentication information along from a front-end proxy), even if the proxy
|
|
carefully strips any incoming value for ``X-Auth-User``, an attacker may be
|
|
able to provide an ``X-Auth_User`` header (with underscore) and bypass this
|
|
protection.
|
|
|
|
In order to prevent such attacks, both Nginx and Apache 2.4+ strip all headers
|
|
containing underscores from incoming requests by default. Django's built-in
|
|
development server now does the same. Django's development server is not
|
|
recommended for production use, but matching the behavior of common production
|
|
servers reduces the surface area for behavior changes during deployment.
|
|
|
|
Mitigated possible XSS attack via user-supplied redirect URLs
|
|
=============================================================
|
|
|
|
Django relies on user input in some cases (e.g.
|
|
``django.contrib.auth.views.login()`` and :doc:`i18n </topics/i18n/index>`)
|
|
to redirect the user to an "on success" URL. The security checks for these
|
|
redirects (namely ``django.utils.http.is_safe_url()``) didn't strip leading
|
|
whitespace on the tested URL and as such considered URLs like
|
|
``\njavascript:...`` safe. If a developer relied on ``is_safe_url()`` to
|
|
provide safe redirect targets and put such a URL into a link, they could suffer
|
|
from a XSS attack. This bug doesn't affect Django currently, since we only put
|
|
this URL into the ``Location`` response header and browsers seem to ignore
|
|
JavaScript there.
|
|
|
|
Denial-of-service attack against ``django.views.static.serve``
|
|
==============================================================
|
|
|
|
In older versions of Django, the :func:`django.views.static.serve` view read
|
|
the files it served one line at a time. Therefore, a big file with no newlines
|
|
would result in memory usage equal to the size of that file. An attacker could
|
|
exploit this and launch a denial-of-service attack by simultaneously requesting
|
|
many large files. This view now reads the file in chunks to prevent large
|
|
memory usage.
|
|
|
|
Note, however, that this view has always carried a warning that it is not
|
|
hardened for production use and should be used only as a development aid. Now
|
|
may be a good time to audit your project and serve your files in production
|
|
using a real front-end web server if you are not doing so.
|
|
|
|
Bugfixes
|
|
========
|
|
|
|
* To maintain compatibility with Python 2.5, Django's vendored version of six,
|
|
``django.utils.six``, has been downgraded to 1.8.0 which is the last
|
|
version to support Python 2.5.
|