CentOS Errata and Security Advisory CESA-2005:417 for x86_64
https://rhn.redhat.com/errata/RHSA-2005-417.html
The following updated files have been uploaded and are currently syncing to the mirrors:
x86_64: arpwatch-2.1a13-9.RHEL4.x86_64.rpm libpcap-0.8.3-9.RHEL4.x86_64.rpm libpcap-0.8.3-9.RHEL4.i386.rpm tcpdump-3.8.2-9.RHEL4.x86_64.rpm
src: tcpdump-3.8.2-9.RHEL4.src.rpm
To get the update run : yum update