(RHSA-2009:0046) Moderate: ntp security update

The Network Time Protocol (NTP) is used to synchronize a computer’s time
with a referenced time source.

A flaw was discovered in the way the ntpd daemon checked the return value
of the OpenSSL EVP_VerifyFinal function. On systems using NTPv4
authentication, this could lead to an incorrect verification of
cryptographic signatures, allowing time-spoofing attacks. (CVE-2009-0021)

Note: This issue only affects systems that have enabled NTP authentication.
By default, NTP authentication is not enabled.

All ntp users are advised to upgrade to the updated packages, which contain
a backported patch to resolve this issue. After installing the update, the
ntpd daemon will restart automatically.