The remote host is missing an update to bind announced via advisory DSA 409-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20409-1

A vulnerability was discovered in BIND, a domain name server, whereby a malicious name server could return authoritative negative responses with a large TTL (time-to-live) value, thereby rendering a domain name unreachable. A successful attack would require that a vulnerable BIND instance submit a query to a malicious nameserver. The bind9 package is not affected by this vulnerability. For the current stable distribution (woody) this problem has been fixed in version 1:8.3.3-2.0woody2. For the unstable distribution (sid) this problem has been fixed in version 1:8.4.3-1. We recommend that you update your bind package.