This update fixes insecure temp file handling of the DHCP server, which could have been exploited locally by a symlink attack, and improves security of the
The dhcp server used easily guessable filenames when creating a new lease file
in the directory /var/lib/dhcp. Since the directory was owned by the nobody
user, another process running under the same user id could trick the server
(which initially runs as root when starting up) into overwriting arbitrary
files via a symlink attack. The DHCP server now runs under its own user id
(dhcpd), the leases file has been moved to /var/lib/dhcp/db, and the rest of
the chroot jail is owned by root.