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

RHSA-2004:440-01 An updated lha package fixes security vulnerability

Files available: lha-1.00-17.3.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