The following errata for CentOS-2 have been built and uploaded to the centos mirror:
RHSA-2007:0384-01 Critical: krb5 security update
Files available: krb5-devel-1.2.2-47.i386.rpm krb5-libs-1.2.2-47.i386.rpm krb5-server-1.2.2-47.i386.rpm krb5-workstation-1.2.2-47.i386.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