The remote host is missing an update to dhcp3 announced via advisory DSA 1833-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201833-1

Several remote vulnerabilities have been discovered in ISC's DHCP implementation: It was discovered that dhclient does not properly handle overlong subnet mask options, leading to a stack-based buffer overflow and possible arbitrary code execution. (CVE-2009-0692) Christoph Biedl discovered that the DHCP server may terminate when receiving certain well-formed DHCP requests, provided that the server configuration mixes host definitions using dhcp-client-identifier and hardware ethernet. This vulnerability only affects the lenny versions of dhcp3-server and dhcp3-server-ldap. (CVE-2009-1892) For the old stable distribution (etch), these problems have been fixed in version 3.0.4-13+etch2. For the stable distribution (lenny), this problem has been fixed in version 3.1.1-6+lenny2. For the unstable distribution (sid), these problems will be fixed soon. We recommend that you upgrade your dhcp3 packages.