The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.
For more information on the security topics covered in this guide, see the following references:
NIST Checklist Details for DoD Consensus Security Configuration Checklist for Red Hat Enterprise Linux 5 2.0: http://web.nvd.nist.gov/view/ncp/repository/checklistDetail?id=294.
NSA Guide to the Secure Configuration of Red Hat Enterprise Linux 5: https://www.nsa.gov/ia/_files/os/redhat/NSA_RHEL_5_GUIDE_v4.2.pdf.
NSA Hardening Tips For Default Installation of Red Hat Enterprise Linux 5: https://www.nsa.gov/ia/_files/factsheets/rhel5-pamphlet-i731.pdf.
NSA Meeting Critical Security Objectives with Security-Enhanced Linux by Peter A. Loscocco and Stephen D. Smalley: https://www.nsa.gov/research/_files/selinux/papers/ottawa01/index.shtml.
NSA SELinux Frequently Asked Questions (FAQ): https://www.nsa.gov/research/selinux/faqs.shtml.
Oracle Tips for Hardening an Oracle Linux Server by Lenz Grimmer and James Morris: https://www.oracle.com/technetwork/articles/servers-storage-admin/tips-harden-oracle-linux-1695888.html.
Oracle Tips for Securing an Oracle Linux Environment by Ginny Henningsen, James Morris, and Lenz Grimmer: https://www.oracle.com/technetwork/articles/servers-storage-admin/secure-linux-env-1841089.html.
SELinux Project Wiki: http://selinuxproject.org/page/Main_Page.
The most up-to-date advice that is available from some of the sources applies to Oracle Linux 5. However, most of the advice is also applicable to Oracle Linux 6.