Django 1.3.5 release notes

Django 1.3.5 addresses two security issues present in previous Django releases in the 1.3 series.

Please be aware that this security release is slightly different from previous ones. Both issues addressed here have been dealt with in prior security updates to Django. In one case, we have received ongoing reports of problems, and in the other we’ve chosen to take further steps to tighten up Django’s code in response to independent discovery of potential problems from multiple sources.

In response to further input received and reports of continuing issues following the previous release, we’re taking additional steps to tighten Host header validation. Rather than attempt to accommodate all features HTTP supports here, Django’s Host header validation attempts to support a smaller, but far more common, subset:

• Hostnames must consist of characters plus hyphen (‘-‘) or dot (‘.’).
• Port, if specified, is numeric.

Any deviation from this will now be rejected, raising the exception .

Redirect poisoning

Since then, two independent audits of the code turned up further potential problems. So, similar to the Host-header issue, we are taking steps to provide tighter validation in response to reported problems (primarily with third-party applications, but to a certain extent also within Django itself). This comes in two parts:

1. A new utility function, , is added; this function takes a URL and a hostname, and checks that the URL is either relative, or if absolute matches the supplied hostname. This function is intended for use whenever user-supplied redirect targets are accepted, to ensure that such redirects cannot lead to arbitrary third-party sites.