CVE-2018-6188

Date: Thu, 25 Jan 2018 13:06:52 -0500
From: Tim Graham <timograham@gmail.com>
Subject: [security@suse.de] Notice of upcoming Django security releases (2.0.2, 1.11.10)

You're receiving this message because you are on the security
prenotification list for the Django web framework; information about
this list can be found in our security policy [1].

In accordance with that policy, a set of security releases will be
issued on Thursday, February 1, 2018 around 1400 UTC. This message
contains descriptions of the issues, descriptions of the changes which
will be made to Django, and the patches which will be applied to Django.

CVE-2018-6188: Information leakage in AuthenticationForm
========================================================

A regression in Django 1.11.8 made
django.contrib.auth.forms.AuthenticationForm run its
confirm_login_allowed() method even if an incorrect password is entered.
This can leak information about a user, depending on what messages
confirm_login_allowed() raises. If confirm_login_allowed() isn't
overridden, an attacker enter an arbitrary username and see if that user has
been set to is_active=False. If confirm_login_allowed() is overridden,
more sensitive details could be leaked.

This issue is fixed with the caveat that AuthenticationForm can no longer
raise the "This account is inactive." error if the authentication backend
rejects inactive users (the default authentication backend, ModelBackend,
has done that since Django 1.10). This issue will be revisited for
Django 2.1 as a fix to address the caveat will likely be too invasive
for inclusion in older versions.

Affected versions
=================

* Django master development branch
* Django 2.0 and 2.0.1
* Django 1.11.8 and 1.11.9

Resolution
==========

Included with this email is are patches implementing the change described
above for each affected version of Django. On the release date, these
patches will be applied to the Django development repository and the
following releases will be issued along with disclosure of the issues:

* Django 2.0.2
* Django 1.11.10

[1] https://www.djangoproject.com/security/


References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2018-6188