NGINX must be configured to pass security attributes to proxies.

If security attributes are not associated with the information being transmitted between components, then access control policies and information flows that depend on these security attributes will not function and unauthorized access may result.

Security attributes are values associated with data content/structure and source/destination objects. These attributes are bound to the user and data objects and may include information about the data's purpose, creator, origin, access restrictions, access permissions, or classification. Specific security attributes used depend on the application or technology context. However, these attributes are used in information systems to implement security policy for access control and flow control for users, data, and traffic. Security attributes may be explicitly or implicitly associated with the information contained within the information system.

This requirement applies to those applications that transmit or receive data between components. Information system components include, for example, mainframes, workstations, servers (e.g., database, email, authentication, web, proxy, file, domain name), input/output devices (e.g., scanners, copiers, printers), network components (e.g., firewalls, routers, gateways, voice and data switches, process controllers, wireless access points, network appliances, sensors), operating systems, virtual machines, middleware, and applications.