https://rhn.redhat.com/errata/RHSA-2005-135.html refers
Updated files are :-
updates/i386/RPMS/squirrelmail-1.4.3a-9.EL3.centos.1.noarch.rpm
updates/i386/SRPMS/squirrelmail-1.4.3a-9.EL3.centos.1.src.rpm
To update run 'yum update squirrelmail'
Updated files are :-
updates/i386/RPMS/squirrelmail-1.4.3a-9.EL3.centos.1.noarch.rpm
updates/i386/SRPMS/squirrelmail-1.4.3a-9.EL3.centos.1.src.rpm
To update run 'yum update squirrelmail'