django/django

===========================
Django 2.2.22 release notes
===========================

*May 6, 2021*

Django 2.2.22 fixes a security issue in 2.2.21.

CVE-2021-32052: Header injection possibility since ``URLValidator`` accepted newlines in input on Python 3.9.5+
===============================================================================================================

On Python 3.9.5+, :class:`~django.core.validators.URLValidator` didn't prohibit
newlines and tabs. If you used values with newlines in HTTP response, you could
suffer from header injection attacks. Django itself wasn't vulnerable because
:class:`~django.http.HttpResponse` prohibits newlines in HTTP headers.

Moreover, the ``URLField`` form field which uses ``URLValidator`` silently
removes newlines and tabs on Python 3.9.5+, so the possibility of newlines
entering your data only existed if you are using this validator outside of the
form fields.

This issue was introduced by the :bpo:`43882` fix.