The following errata for CentOS-2 have been built and uploaded to the centos mirror:
RHSA-2007:0532-01 Moderate: apache security update
Files available: apache-1.3.27-12.ent.c2.1.i386.rpm apache-devel-1.3.27-12.ent.c2.1.i386.rpm apache-manual-1.3.27-12.ent.c2.1.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