The following errata for CentOS-2 have been built and uploaded the the centos mirror:

RHSA-2004:505-01 Updated kernel packages fix security vulnerability

Files available: kernel-2.4.9-e.57.athlon.rpm kernel-smp-2.4.9-e.57.athlon.rpm kernel-BOOT-2.4.9-e.57.i386.rpm kernel-doc-2.4.9-e.57.i386.rpm kernel-headers-2.4.9-e.57.i386.rpm kernel-source-2.4.9-e.57.i386.rpm kernel-2.4.9-e.57.i686.rpm kernel-debug-2.4.9-e.57.i686.rpm kernel-enterprise-2.4.9-e.57.i686.rpm kernel-smp-2.4.9-e.57.i686.rpm kernel-summit-2.4.9-e.57.i686.rpm

More details are available from the RedHat web site at https://rhn.redhat.com/errata/rh21as-errata.html

The easy way to make sure you are up to date with all the latest patches is to run: # yum update