===========================

Django 1.4.20 release notes

===========================

*March 18, 2015*

Django 1.4.20 fixes one security issue in 1.4.19.

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()``) accepted URLs with

leading control characters and so considered URLs like ``\x08javascript:...``

safe. This issue doesn't affect Django currently, since we only put this URL

into the ``Location`` response header and browsers seem to ignore JavaScript

there. Browsers we tested also treat URLs prefixed with control characters such

as ``%08//example.com`` as relative paths so redirection to an unsafe target

isn't a problem either.

However, if a developer relies on ``is_safe_url()`` to

provide safe redirect targets and puts such a URL into a link, they could

suffer from an XSS attack as some browsers such as Google Chrome ignore control

characters at the start of a URL in an anchor ``href``.