Django Software Foundation · Django · CVE-2011-4137
**Name of the Vulnerable Software and Affected Versions**
Django versions prior to 1.2.7
Django versions 1.3.x prior to 1.3.1
**Description**
The issue is related to the `verify exists` functionality in the `URLField` implementation, which relies on Python libraries that attempt to access an arbitrary URL with no timeout. This allows remote attackers to cause a denial of service by consuming resources via a URL associated with a slow response, a completed TCP connection with no application data sent, or a large amount of application data.
**Recommendations**
For Django versions prior to 1.2.7, update to version 1.2.7 or later.
For Django versions 1.3.x prior to 1.3.1, update to version 1.3.1 or later.