The remote host is missing an update to python-django announced via advisory DSA 1905-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201905-1

The forms library of python-django, a high-level Python web development framework, is using a badly chosen regular expression when validating email addresses and URLs. An attacker can use this to perform denial of service attacks (100% CPU consumption) due to bad backtracking via a specially crafted email address or URL which is validated by the django forms library. python-django in the oldstable distribution (etch), is not affected by this problem. For the stable distribution (lenny), this problem has been fixed in version 1.0.2-1+lenny2. For the testing distribution (squeeze), this problem will be fixed soon. For the unstable distribution (sid), this problem has been fixed in version 1.1.1-1. We recommend that you upgrade your python-django packages.