The security access policy that contains fixed security attributes that are used by the system to determine a user’s access to a file or object is Mandatory Access Control (MAC). MAC is a type of access control model that assigns permissions to users and objects based on their security labels, which indicate their level of sensitivity or trustworthiness. MAC is enforced by the system or the network, rather than by the owner or the creator of the object, and it cannot be modified or overridden by the users. MAC can provide some benefits for security, such as enhancing the confidentiality and the integrity of the data, preventing unauthorized access or disclosure, and supporting the audit and compliance activities. MAC is commonly used in military or government environments, where the data is classified according to its level of sensitivity, such as top secret, secret, confidential, or unclassified. The users are granted security clearance based on their level of trustworthiness, such as their background, their role, or their need to know. The users can only access the objects that have the same or lower security classification than their security clearance, and the objects can only be accessed by the users that have the same or higher security clearance than their security classification. This is based on the concept of no read up and no write down, which requires that a user can only read data of lower or equal sensitivity level, and can only write data of higher or equal sensitivity level. MAC contains fixed security attributes that are used by the system to determine a user’s access to a file or object, by using the following methods:

• Assigning security labels to the users and the objects, which consist of a security classification and a set of security categories. The security classification indicates the level of sensitivity of the data, such as top secret, secret, confidential, or unclassified. The security categories indicate the subject matter or the scope of the data, such as nuclear, military, or intelligence. The security labels are attached to the users and the objects as metadata or tags, and they cannot be changed or removed by the users.
• Comparing the security labels of the users and the objects, using a reference monitor or an access control matrix. The reference monitor is a software component that intercepts and evaluates the requests for access to the objects, and grants or denies the access based on the security labels of the users and the objects. The access control matrix is a data structure that lists the users and the objects, and the permissions that each user has on each object, based on the security labels of the users and the objects.

The best location in a network to place Virtual Private Network (VPN) devices when an internal review reveals network design flaws in remote access is in a dedicated Demilitarized Zone (DMZ). A DMZ is a network segment that is located between the internal network and the external network, such as the internet. A DMZ is used to host the services or devices that need to be accessed by both the internal and external users, such as web servers, email servers, or VPN devices. A VPN device is a device that enables the establishment of a VPN, which is a secure and encrypted connection between two networks or endpoints over a public network, such as the internet. Placing the VPN devices in a dedicated DMZ can help to improve the security and performance of the remote access, as well as to isolate the VPN devices from the internal network and the external network. Placing the VPN devices in its own separate VLAN, at the ISP, or outside the external firewall are not the best locations, as they may expose the VPN devices to more risks, reduce the control over the VPN devices, or create a single point of failure for the remote access. References: CISSP All-in-One Exam Guide, Eighth Edition, Chapter 6: Communication and Network Security, page 729; Official (ISC)2 Guide to the CISSP CBK, Fifth Edition, Chapter 4: Communication and Network Security, page 509.

Enterprise security architecture is the framework that defines the security policies, standards, guidelines, and controls that govern the security of an organization’s information systems and assets. Enterprise security architecture must be scalable to address the security concerns raised by the integration of third-party identity services, such as Identity as a Service (IDaaS) or federated identity management. Scalability means that the enterprise security architecture can accommodate the increased complexity, diversity, and volume of identity and access management transactions and interactions that result from the integration of external identity providers and consumers. Scalability also means that the enterprise security architecture can adapt to the changing security requirements and threats that may arise from the integration of third-party identity services.