---
title: "Informacje o wydaniu Django 1.6.11"
version: 5.1
locale: pl
source: https://docs.djangoproject.com/pl/5.1/releases/1.6.11/
canonical: https://djangodocs.dev/pl/5.1/releases/1.6.11/
---
# Informacje o wydaniu Django 1.6.11

*March 18, 2015*

Django 1.6.11 fixes two security issues in 1.6.10.

## Denial-of-service possibility with `strip_tags()`

Last year [`strip_tags()`](/pl/5.1/ref/utils/#django.utils.html.strip_tags)  was changed to work
iteratively. The problem is that the size of the input it’s processing can
increase on each iteration which results in an infinite loop in
`strip_tags()`. This issue only affects versions of Python that haven’t
received [a bugfix in HTMLParser](https://bugs.python.org/issue?@action=redirect&bpo=20288); namely Python \< 2.7.7 and
3.3.5. Some operating system vendors have also backported the fix for the
Python bug into their packages of earlier versions.

To remedy this issue, `strip_tags()` will now return the original input if
it detects the length of the string it’s processing increases. Remember that
absolutely NO guarantee is provided about the results of `strip_tags()` being
HTML safe. So NEVER mark safe the result of a `strip_tags()` call without
escaping it first, for example with [`escape()`](/pl/5.1/ref/utils/#django.utils.html.escape).

## 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 [i18n](/pl/5.1/topics/i18n/))
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`.