The remote host is missing an update to djbdns announced via advisory DSA 1831-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201831-1

Matthew Dempsky discovered that Daniel J. Bernstein's djbdns, a Domain Name System server, does not constrain offsets in the required manner, which allows remote attackers with control over a third-party subdomain served by tinydns and axfrdns, to trigger DNS responses containing arbitrary records via crafted zone data for this subdomain. The old stable distribution (etch) does not contain djbdns. For the stable distribution (lenny), this problem has been fixed in version 1.05-4+lenny1. For the unstable distribution (sid), this problem has been fixed in version 1.05-5. We recommend that you upgrade your djbdns package.