The remote host is missing an update to isc-dhcp announced via advisory DSA 2184-1.

The oldstable distribution (lenny) is not affected by this problem. For the stable distribution (squeeze), this problem has been fixed in version 4.1.1-P1-15+squeeze1. For the testing distribution (wheezy) and the unstable distribution (sid), this problem has been fixed in version 4.1.1-P1-16. We recommend that you upgrade your isc-dhcp packages. https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202184-1

It was discovered that the ISC DHCPv6 server does not correctly process requests which come from unexpected source addresses, leading to an assertion failure and a daemon crash.