django -- multiple vulnerabilities

The Django Project reports:

These security releases fix four issues: one potential phishing
vector, one denial-of-service vector, an information leakage issue,
and a range of XML vulnerabilities.

Host header poisoning
an attacker could cause Django to generate and display URLs that
link to arbitrary domains. This could be used as part of a phishing
attack. These releases fix this problem by introducing a new
setting, ALLOWED_HOSTS, which specifies a whitelist of domains your
site is known to respond to.
Important: by default Django 1.3.6 and 1.4.4 set ALLOWED_HOSTS to
allow all hosts. This means that to actually fix the security
vulnerability you should define this setting yourself immediately
after upgrading.

Formset denial-of-service
an attacker can abuse Django’s tracking of the number of forms in
a formset to cause a denial-of-service attack. This has been fixed
by adding a default maximum number of forms of 1,000. You can still
manually specify a bigger max_num, if you wish, but 1,000 should be
enough for anyone.

XML attacks
Django’s serialization framework was vulnerable to attacks via XML
entity expansion and external references; this is now fixed.
However, if you’re parsing arbitrary XML in other parts of your
application, we recommend you look into the defusedxml Python
packages which remedy this anywhere you parse XML, not just via
Django’s serialization framework.

Data leakage via admin history log
Django’s admin interface could expose supposedly-hidden
information via its history log. This has been fixed.