The remote host is missing an update to isc-dhcp announced via advisory DSA 2216-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202216-1

Sebastian Krahmer and Marius Tomaschewski discovered that dhclient of isc-dhcp, a DHCP client, is not properly filtering shell meta-characters in certain options in DHCP server responses. These options are reused in an insecure fashion by dhclient scripts. This allows an attacker to execute arbitrary commands with the privileges of such a process by sending crafted DHCP options to a client using a rogue server. For the oldstable distribution (lenny), this problem has been fixed in additional update for dhcp3. For the stable distribution (squeeze), this problem has been fixed in version 4.1.1-P1-15+squeeze2. For the testing distribution (wheezy), this problem will be fixed soon. For the unstable distribution (sid), this problem has been fixed in version 4.1.1-P1-16.1. We recommend that you upgrade your isc-dhcp packages.