CentOS Errata and Security Advisory 2005:357
https://rhn.redhat.com/errata/RHSA-2005-357.html
The following updated files have been uploaded and are currently syncing to the mirrors for both CentOS 4.0 and 4.1:
i386: gzip-1.3.3-15.rhel4.i386.rpm
src: gzip-1.3.3-15.rhel4.src.rpm