Changes 1.2.2:
As of the 1.2 release, the core Django framework includes a system, enabled by
default, for detecting and preventing cross-site request forgery (CSRF) attacks
against Django-powered applications. Previous Django releases provided
a different, optionally-enabled system for the same purpose.

The Django 1.2 CSRF protection system involves the generation of a random
token, inserted as a hidden field in outgoing forms. The same value is also
set in a cookie, and the cookie value and form value are compared on submission.

The provided template tag for inserting the CSRF token into forms --
{% csrf_token %} -- explicitly trusts the cookie value, and displays it as-is.
Thus, an attacker who is able to tamper with the value of the CSRF cookie can
cause arbitrary content to be inserted, unescaped, into the outgoing HTML of
the form, enabling cross-site scripting (XSS) attacks.

This issue was first reported via a public ticket in Django's Trac instance;
while being triaged it was then independently reported, with broader
description, by Jeff Balogh of Mozilla.

(adam)