January 29, 2002, 12:00 AM — With businesses, organizations, and government agencies exploiting
interactive Web-based technology to deliver online services to
employees, customers, and suppliers, Web servers have become the pivot
point that connects authorized users to databases and internal network
applications. Unfortunately, Web server architectures are exceedingly
susceptible to security attacks, especially those Web server
architectures that are built on universal OSes.
Intrusion detection systems and firewalls do not adequately reduce the
security hazards presented by applications that implement dynamic
content or transaction services. Firewalls impart basic protection for
services such as FTP and SMTP, but they were not designed to protect
hosted applications. In addition, firewalls offer little security
against manipulations of HTTP traffic.
Nor were intrusion detection tools designed to address Web server
security issues. Although most security measures are based on a
reactive model to electronic hostilities, companies can take proactive
measures to secure their applications against attacks.
Trusted operating systems
Enter the resurrection of the TOS (trusted operating system), a relic
from the early '80s developed for military and government security.
Considered by many to be too expensive and complicated to implement and
maintain, TOSes failed to catch on when introduced to the commercial
sector and instead were pigeonholed into the financial industry. With
today's corporate Web servers serving as the gateway to mission-
critical e-business applications and information, however, IT
departments should take a hard look at the new generation of TOSes.
View illustration, "Compartmentalization is the key."
A TOS is simply a security-hardened version of a standard OS. TOSes
come in a variety of flavors, including Sun Solaris, Hewlett-Packard's
HP-UX, IBM AIX, Linux, and Microsoft Windows NT. Trusted versions of
these operating systems isolate key OS functions into separate
compartments, limiting the ability of intruders to access and control
critical parts of a computer system, as well as preventing
administrators from making inadvertent, harmful changes.
Naturally, TOSes cost more than their standard OS counterparts, and
they are more difficult to administer. But because they provide a level
of protection beyond firewalls and intrusion detection systems, they
are suitable for e-commerce systems that are key to your business and
its relationships with customers and business partners.
Then and now
Early TOSes were marketed entirely in the government arena. Designed to
solve military problems associated with information auditing, these
systems were rigid and nearly impossible to integrate with commercial