Django security releases issued: 4.0.1, 3.2.11, and 2.2.26

Posted by Carlton Gibson on Jan. 4, 2022

In accordance with our security release policy, the Django team is issuing Django 4.0.1, Django 3.2.11, and Django 2.2.26. These release addresses the security issues detailed below. We encourage all users of Django to upgrade as soon as possible.

CVE-2021-45115: Denial-of-service possibility in UserAttributeSimilarityValidator

UserAttributeSimilarityValidator incurred significant overhead evaluating submitted password that were artificially large in relative to the comparison values. On the assumption that access to user registration was unrestricted this provided a potential vector for a denial-of-service attack.

In order to mitigate this issue, relatively long values are now ignored by UserAttributeSimilarityValidator.

Thanks Chris Bailey for the report.

This issue has severity "medium" according to the Django security policy.

CVE-2021-45116: Potential information disclosure in dictsort template filter

Due to leveraging the Django Template Language's variable resolution logic, the dictsort template filter was potentially vulnerable to information disclosure or unintended method calls, if passed a suitably crafted key.

In order to avoid this possibility, dictsort now works with a restricted resolution logic, that will not call methods, nor allow indexing on dictionaries.

As a reminder, all untrusted user input should be validated before use.

Thanks to Dennis Brinkrolf for the report.

This issue has severity "low" according to the Django security policy.

CVE-2021-45452: Potential directory-traversal via Storage.save()

Storage.save() allowed directory-traversal if directly passed suitably crafted file names.

Thanks to Dennis Brinkrolf for the report.

This issue has severity "low" according to the Django security policy.

Affected supported versions

  • Django main branch
  • Django 4.0
  • Django 3.2
  • Django 2.2

Resolution

Patches to resolve the issue have been applied to Django's main branch and to the 4.0, 3.2, and 2.2 release branches. The patches may be obtained from the following changesets.

CVE-2021-45115:

CVE-2021-45116:

CVE-2021-45452:

The following releases have been issued:

The PGP key ID used for these releases is Carlton Gibson: E17DF5C82B4F9D00.

General notes regarding security reporting

As always, we ask that potential security issues be reported via private email to security@djangoproject.com, and not via Django's Trac instance or the django-developers list. Please see our security policies for further information.

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