Editing Common Criteria (section)

===Value of certification===
Common Criteria certification cannot guarantee security, but it can ensure that claims about the security attributes of the evaluated product were independently verified. In other words, products evaluated against a Common Criteria standard exhibit a clear chain of evidence that the process of specification, implementation, and evaluation has been conducted in a rigorous and standard manner.

Various [[Microsoft]] Windows versions, including [[Windows Server 2003]] and [[Windows XP]], have been certified,<ref>{{Cite web |date=2005-12-14 |title=Versions of Windows obtain Common Criteria EAL level 4+ |url=http://www.nist.org/news.php?extend.37 |archive-url=https://web.archive.org/web/20061014120129/http://www.nist.org/news.php?extend.37 |archive-date=2006-10-14 |website=Network Information Security & Technology News}}</ref> but security patches to address security vulnerabilities are still getting published by Microsoft for these Windows systems. This is possible because the process of obtaining a Common Criteria certification allows a vendor to restrict the analysis to certain security features and to make certain assumptions about the operating environment and the strength of threats faced by the product in that environment. Additionally, the CC recognizes a need to limit the scope of evaluation in order to provide cost-effective and useful security certifications, such that evaluated products are examined to a level of detail specified by the assurance level or PP.  Evaluations activities are therefore only performed to a certain depth, use of time, and resources and offer reasonable assurance for the intended environment.

In the Microsoft case, the assumptions include A.PEER: 
<blockquote>
"Any other systems with which the TOE communicates are assumed to be under the same management control and operate under the same security policy constraints. The TOE is applicable to networked or distributed environments only if the entire network operates under the same constraints and resides within a single management domain. There are no security requirements that address the need to trust external systems or the communications links to such systems."
</blockquote>

This assumption is contained in the [[Controlled Access Protection Profile]] (CAPP) to which their products adhere. Based on this and other assumptions, which may not be realistic for the common use of general-purpose operating systems, the claimed security functions of the Windows products are evaluated. Thus they should only be considered secure in the assumed, specified circumstances, also known as the ''evaluated configuration''.

Whether you run Microsoft Windows in the precise evaluated configuration or not, you should apply Microsoft's security patches for the vulnerabilities in Windows as they continue to appear. If any of these security vulnerabilities are exploitable in the product's evaluated configuration, the product's Common Criteria certification should be voluntarily withdrawn by the vendor. Alternatively, the vendor should re-evaluate the product to include the application of patches to fix the security vulnerabilities within the evaluated configuration. Failure by the vendor to take either of these steps would result in involuntary withdrawal of the product's certification by the certification body of the country in which the product was evaluated.

The certified Microsoft Windows versions remain at [[Evaluation Assurance Level|EAL4+]] without including the application of any Microsoft security vulnerability patches in their evaluated configuration. This shows both the limitation and strength of an evaluated configuration.