Making certain that the web server has not been updated by an unauthorized user is always a concern. Adding patches, functions, and modules that are untested and not part of the baseline opens the possibility for security risks. The web server must offer, and not hinder, a method that allows for the quick and easy reinstallation of a verified and patched baseline to guarantee the production web server is up-to-date and has not been modified to add functionality or expose security risks. When the web server does not offer a method to roll back to a clean baseline, external methods, such as a baseline snapshot or virtualizing the web server, can be used.
Review the web server documentation and deployed configuration to determine if the web server offers the capability to reinstall from a known state. If the web server does not offer this capability, determine if the web server, in any manner, prohibits the reinstallation of a known state. If the web server does prohibit the reinstallation to a known state, this is a finding.
Configure the web server to augment and not hinder the reinstallation of a known and stable baseline.