The remote host is missing an update to mydns announced via advisory DSA 1434-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201434-1

It was discovered that in MyDNS, a domain name server with database backend, the daemon could be crashed through malicious remote update requests, which may lead to denial of service. For the stable distribution (etch), this problem has been fixed in version 1:1.1.0-7etch1. The old stable distribution (sarge) is not affected. For the unstable distribution (sid), this problem has been fixed in version 1.1.0-8. We recommend that you upgrade your mydns packages.