61 lines
2.6 KiB
Plaintext
61 lines
2.6 KiB
Plaintext
==========================
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Django 1.4.3 release notes
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==========================
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*December 10, 2012*
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Django 1.4.3 addresses two security issues present in previous Django releases
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in the 1.4 series.
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Please be aware that this security release is slightly different from previous
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ones. Both issues addressed here have been dealt with in prior security updates
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to Django. In one case, we have received ongoing reports of problems, and in
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the other we've chosen to take further steps to tighten up Django's code in
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response to independent discovery of potential problems from multiple sources.
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Host header poisoning
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=====================
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Several earlier Django security releases focused on the issue of poisoning the
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HTTP Host header, causing Django to generate URLs pointing to arbitrary,
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potentially-malicious domains.
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In response to further input received and reports of continuing issues
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following the previous release, we're taking additional steps to tighten Host
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header validation. Rather than attempt to accommodate all features HTTP
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supports here, Django's Host header validation attempts to support a smaller,
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but far more common, subset:
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* Hostnames must consist of characters ``[A-Za-z0-9]`` plus hyphen ('-') or dot
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('.').
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* IP addresses -- both IPv4 and IPv6 -- are permitted.
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* Port, if specified, is numeric.
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Any deviation from this will now be rejected, raising the exception
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:exc:`django.core.exceptions.SuspiciousOperation`.
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Redirect poisoning
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==================
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Also following up on a previous issue: in July of this year, we made changes to
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Django's HTTP redirect classes, performing additional validation of the scheme
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of the URL to redirect to (since, both within Django's own supplied
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applications and many third-party applications, accepting a user-supplied
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redirect target is a common pattern).
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Since then, two independent audits of the code turned up further potential
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problems. So, similar to the Host-header issue, we are taking steps to provide
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tighter validation in response to reported problems (primarily with third-party
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applications, but to a certain extent also within Django itself). This comes in
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two parts:
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1. A new utility function, ``django.utils.http.is_safe_url``, is added; this
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function takes a URL and a hostname, and checks that the URL is either
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relative, or if absolute matches the supplied hostname. This function is
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intended for use whenever user-supplied redirect targets are accepted, to
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ensure that such redirects cannot lead to arbitrary third-party sites.
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2. All of Django's own built-in views -- primarily in the authentication system
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-- which allow user-supplied redirect targets now use ``is_safe_url`` to
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validate the supplied URL.
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