CentOS Errata and Security Advisory 2005:505
https://rhn.redhat.com/errata/RHSA-2005-505.html
The following updated files have been uploaded and are currently syncing to the mirrors for both CentOS 4.0 and 4.1:
i386: arpwatch-2.1a13-10.RHEL4.i386.rpm libpcap-0.8.3-10.RHEL4.i386.rpm tcpdump-3.8.2-10.RHEL4.i386.rpm
src: tcpdump-3.8.2-10.RHEL4.src.rpm