ntp -- multiple vulnerabilities

CERT reports:

The Network Time Protocol (NTP) provides networked
systems with a way to synchronize time for various
services and applications. ntpd version 4.2.7 and
previous versions allow attackers to overflow several
buffers in a way that may allow malicious code to
be executed. ntp-keygen prior to version 4.2.7p230
also uses a non-cryptographic random number generator
when generating symmetric keys.
The buffer overflow vulnerabilities in ntpd may
allow a remote unauthenticated attacker to execute
arbitrary malicious code with the privilege level
of the ntpd process. The weak default key and
non-cryptographic random number generator in
ntp-keygen may allow an attacker to gain
information regarding the integrity checking
and authentication encryption schemes.