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

RHBA-2004:401-07 Updated util-linux and mount packages
RHBA-2004:458-04 Updated sh-utils package
RHBA-2004:459-04 Updated fileutils package
RHBA-2004:469-06 Updated piranha package
RHBA-2004:476-06 Updated rusers packages
RHBA-2004:487-04 Updated ucd-snmp packages
RHBA-2004:493-04 Updated clumanager package
RHBA-2004:496-06 Updated psacct package
RHBA-2004:503-15 Updated sysstat package
RHBA-2004:515-05 Updated kudzu packages
RHBA-2004:527-03 Updated shadow-utils package
RHBA-2004:533-03 Updated nss_ldap package
RHBA-2004:534-07 Updated openssh packages
RHBA-2004:575-03 Updated pam packages
RHBA-2004:576-02 Updated net-tools package
RHBA-2004:587-04 Updated glibc packages
RHBA-2004:619-06 Updated initscripts package
RHBA-2004:623-06 Updated gcc packages
RHEA-2004:516-03 Updated pciutils packages
RHEA-2004:548-03 Updated amanda packages
RHEA-2004:605-04 Updated rsh package

Files available:
amanda-2.4.4p3-1.21as.i386.rpm
amanda-client-2.4.4p3-1.21as.i386.rpm
amanda-devel-2.4.4p3-1.21as.i386.rpm
amanda-server-2.4.4p3-1.21as.i386.rpm
clumanager-1.0.28-1.i386.rpm
cpp-2.96-129.7.2.i386.rpm
fileutils-4.1-10.8.i386.rpm
gcc-2.96-129.7.2.i386.rpm
gcc-c++-2.96-129.7.2.i386.rpm
gcc-chill-2.96-129.7.2.i386.rpm
gcc-g77-2.96-129.7.2.i386.rpm
gcc-java-2.96-129.7.2.i386.rpm
gcc-objc-2.96-129.7.2.i386.rpm
glibc-2.2.4-32.18.i386.rpm
glibc-2.2.4-32.18.i686.rpm
glibc-common-2.2.4-32.18.i386.rpm
glibc-devel-2.2.4-32.18.i386.rpm
glibc-profile-2.2.4-32.18.i386.rpm
initscripts-6.47.13-1.c2.1.i386.rpm
kudzu-0.99.42.3.6-1.i386.rpm
kudzu-devel-0.99.42.3.6-1.i386.rpm
libstdc++-2.96-129.7.2.i386.rpm
libstdc++-devel-2.96-129.7.2.i386.rpm
losetup-2.11g-8.i386.rpm
mount-2.11g-8.i386.rpm
net-tools-1.60-19.AS21.2.i386.rpm
nscd-2.2.4-32.18.i386.rpm
nss_ldap-189-12.i386.rpm
openssh-3.1p1-17.i386.rpm
openssh-askpass-3.1p1-17.i386.rpm
openssh-askpass-gnome-3.1p1-17.i386.rpm
openssh-clients-3.1p1-17.i386.rpm
openssh-server-3.1p1-17.i386.rpm
pam-0.75-46.62.i386.rpm
pam-devel-0.75-46.62.i386.rpm
pciutils-2.1.8-26.3.i386.rpm
pciutils-devel-2.1.8-26.3.i386.rpm
perl-5.6.1-37.1.99ent.c2.1.i386.rpm
perl-CGI-2.752-37.1.99ent.c2.1.i386.rpm
perl-CPAN-1.59_54-37.1.99ent.c2.1.i386.rpm
perl-DB_File-1.75-37.1.99ent.c2.1.i386.rpm
perl-NDBM_File-1.75-37.1.99ent.c2.1.i386.rpm
perl-suidperl-5.6.1-37.1.99ent.c2.1.i386.rpm
piranha-0.7.0.1-1.i386.rpm
psacct-6.3.2-12.21as.i386.rpm
rsh-0.17-18.AS21.3.i386.rpm
rsh-server-0.17-18.AS21.3.i386.rpm
rusers-0.17-20.AS21.3.i386.rpm
rusers-server-0.17-20.AS21.3.i386.rpm
sh-utils-2.0.11-5.2.i386.rpm
shadow-utils-20000902-17.c2.1.i386.rpm
sysstat-5.0.5-10.21as.i386.rpm
sysstat-isag-5.0.5-10.21as.i386.rpm
tetex-1.0.7-38.4.c2.1.i386.rpm
tetex-afm-1.0.7-38.4.c2.1.i386.rpm
tetex-doc-1.0.7-38.4.c2.1.i386.rpm
tetex-dvilj-1.0.7-38.4.c2.1.i386.rpm
tetex-dvips-1.0.7-38.4.c2.1.i386.rpm
tetex-fonts-1.0.7-38.4.c2.1.i386.rpm
tetex-latex-1.0.7-38.4.c2.1.i386.rpm
tetex-xdvi-1.0.7-38.4.c2.1.i386.rpm
ucd-snmp-4.2.5-8.AS21.4.i386.rpm
ucd-snmp-devel-4.2.5-8.AS21.4.i386.rpm
ucd-snmp-utils-4.2.5-8.AS21.4.i386.rpm
util-linux-2.11f-20.5.i386.rpm

Notes:
initscripts modified to remove Red Hat trademark
perl is a new centos release with the correct centos release suffix
shadow-utils has been modified to fix bug #125510
tetex is a new centos release with the correct centos release suffix

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