What role do Shared Services network zones play in connection with the CDE?

Shared Services network zones play a crucial role in managing and securing the Cardholder Data Environment (CDE) by functioning similarly to a Demilitarized Zone (DMZ). This setup allows the shared services to handle requests from both untrusted and trusted users, creating a controlled interface between different network zones. By facilitating this separation, organizations can effectively manage data flow and interactions while enforcing security policies.

This approach helps maintain the integrity and confidentiality of the CDE by ensuring that only vetted and authorized communications occur between the CDE and the external or broader corporate networks. Because shared services handle requests from different user categories, they must implement stringent access controls and monitoring to detect and prevent unauthorized access to sensitive cardholder data.

The other options do not accurately describe the function of shared services in relation to the CDE. For example, providing resources only to trusted users would not encompass the necessary interaction required with untrusted users. Isolating the corporate network completely would hinder the interaction needed for shared services, and serving as backups for user data doesn’t accurately represent the primary security and functionality objective of such zones in a PCI DSS context.