The MITRE CVE dictionary describes this issue as:
The XML libraries for Python 3.4, 3.3, 3.2, 3.1, 2.7, and 2.6, as used in OpenStack Keystone Essex, Folsom, and Grizzly; Compute (Nova) Essex and Folsom; Cinder Folsom; Django; and possibly other products allow remote attackers to cause a denial of service (resource consumption and crash) via an XML Entity Expansion (XEE) attack.
Find out more about CVE-2013-1664 from the
MITRE CVE dictionary dictionary and
This issue affects the versions of python as shipped with Red Hat Enterprise Linux 5, 6 and 7. Red Hat Product Security has rated this issue as having Moderate security impact. This issue is not currently planned to be addressed in future updates.