CentOS Errata and Security Advisory 2009:0207
https://rhn.redhat.com/errata/RHSA-2008-0207.html
The following updated files have been uploaded and are currently syncing to the mirrors:
i386: firefox-1.5.0.12-0.14.el4.centos.i386.rpm
src: firefox-1.5.0.12-0.14.el4.centos.src.rpm