The following errata for CentOS-2 have been built and uploaded the the centos mirror:
RHSA-2004:418-01 Updated kernel packages fix security vulnerability
Files available: kernel-BOOT-2.4.9-e.48.i386.rpm: kernel-doc-2.4.9-e.48.i386.rpm: kernel-headers-2.4.9-e.48.i386.rpm: kernel-source-2.4.9-e.48.i386.rpm: kernel-2.4.9-e.48.i686.rpm: kernel-debug-2.4.9-e.48.i686.rpm: kernel-enterprise-2.4.9-e.48.i686.rpm: kernel-smp-2.4.9-e.48.i686.rpm: kernel-summit-2.4.9-e.48.i686.rpm: kernel-smp-2.4.9-e.48.athlon.rpm: kernel-2.4.9-e.48.athlon.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