# Django 2.1.8.dev20190330215650 documentation

# Django 1.5.4 release notes

September 14, 2013

This is Django 1.5.4, the fourth release in the Django 1.5 series. It addresses two security issues and one bug.

## Denial-of-service via password hashers

In previous versions of Django, no limit was imposed on the plaintext length of a password. This allowed a denial-of-service attack through submission of bogus but extremely large passwords, tying up server resources performing the (expensive, and increasingly expensive with the length of the password) calculation of the corresponding hash.

As of 1.5.4, Django's authentication framework imposes a 4096-byte limit on passwords, and will fail authentication with any submitted password of greater length.

## Corrected usage of `sensitive_post_parameters()` in `django.contrib.auth`’s admin

The decoration of the `add_view` and `user_change_password` user admin views with `sensitive_post_parameters()` did not include `method_decorator()` (required since the views are methods) resulting in the decorator not being properly applied. This usage has been fixed and `sensitive_post_parameters()` will now throw an exception if it's improperly used.

## Bugfixes

- Fixed a bug that prevented a `QuerySet` that uses `prefetch_related()` from being pickled and unpickled more than once (the second pickling attempt raised an exception) (#21102).