The remote host is missing an update to python-dns announced via advisory DSA 1619-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201619-1

Multiple weaknesses have been identified in PyDNS, a DNS client implementation for the Python language. Dan Kaminsky identified a practical vector of DNS response spoofing and cache poisoning, exploiting the limited entropy in a DNS transaction ID and lack of UDP source port randomization in many DNS implementations. Scott Kitterman noted that python-dns is vulnerable to this predictability, as it randomizes neither its transaction ID nor its source port. Taken together, this lack of entropy leaves applications using python-dns to perform DNS queries highly susceptible to response forgery. The Common Vulnerabilities and Exposures project identifies this class of weakness as CVE-2008-1447. For the stable distribution (etch), these problems have been fixed in version 2.3.0-5.2+etch1. We recommend that you upgrade your python-dns package.