Debian: DSA-2217-1 Critical: Dhcp3 Remote Command Execution Threat

Sebastian Krahmer and Marius Tomaschewski discovered that dhclient of
dhcp3, a DHCP client, is not properly filtering shell meta-charactersin 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.

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: http://www.debian.org/security/