The remote host is missing an update to dhcp announced via advisory DSA 1388-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201388-1

It was discovered that dhcp, a DHCP server for automatic IP address assignment, didn't correctly allocate space for network replies. This could potentially allow a malicious DHCP client to execute arbitary code upon the DHCP server. For the old stable distribution (sarge), this problem has been fixed in version 2.0pl5-19.1sarge3. For the stable distribution (etch), this problem has been fixed in version 2.0pl5-19.5etch1. For the unstable distribution (sid), this problem will be fixed shortly. We recommend that you upgrade your dhcp package.