The remote host is missing an update to dhcp3 announced via advisory DSA 2217-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202217-1

Sebastian Krahmer and Marius Tomaschewski discovered that dhclient of dhcp3, 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 version 3.1.1-6+lenny5. For the stable (squeeze), testing (wheezy) and unstable (sid) distributions, this problem has been fixed in an additional update for isc-dhcp. We recommend that you upgrade your dhcp3 packages.