The following errata for CentOS-2 have been built and uploaded to the centos mirror:
RHSA-2006:0698-01 Important: openssh security update
Files available: openssh-3.1p1-21.i386.rpm openssh-askpass-3.1p1-21.i386.rpm openssh-askpass-gnome-3.1p1-21.i386.rpm openssh-clients-3.1p1-21.i386.rpm openssh-server-3.1p1-21.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