CentOS Errata and Security Advisory 2009:0046
https://rhn.redhat.com/errata/RHSA-2009-0046.html
The following updated files have been uploaded and are currently syncing to the mirrors:
s390: updates/s390/RPMS/ntp-4.2.0.a.20040617-8.el4_7.1.s390.rpm
s390x: updates/s390x/RPMS/ntp-4.2.0.a.20040617-8.el4_7.1.s390x.rpm