CVE 2011-4140
The CSRF protection mechanism in Django through 1.2.7 and 1.3.x through 1.3.1 does not properly handle web-server configurations supporting arbitrary HTTP Host headers, which allows remote attackers to trigger unauthenticated forged requests via vectors involving a DNS CNAME record and a web page containing JavaScript code.
See the 
CVE page on Mitre.org
for more details.
