The remote host is missing an update to bind9 announced via advisory DSA 1603-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201603-1

Dan Kaminsky discovered that properties inherent to the DNS protocol lead to practical DNS cache poisoning attacks. Among other things, successful attacks can lead to misdirected web traffic and email rerouting. This update changes Debian's BIND 9 packages to implement the recommended countermeasure: UDP query source port randomization. This change increases the size of the space from which an attacker has to guess values in a backwards-compatible fashion and makes successful attacks significantly more difficult. For more details on the impact of this update and steps to take to ensure a smooth upgrade, please visit the referenced security advisory. For the stable distribution (etch), this problem has been fixed in version 9.3.4-2etch3. For the unstable distribution (sid), this problem will be fixed soon. We recommend that you upgrade your bind9 package.