CISSP Security Architecture and Engineering — Timed 20 Questions

Question 1

An organization is implementing a PKI for internal use. To ensure that certificate revocation status is checked in real-time without relying on periodic CRL downloads, which mechanism should be used?

Accepted Answer

OCSP stapling. The Online Certificate Status Protocol (OCSP) is a protocol used for obtaining the revocation status of an X.509 digital certificate in real-time. It was created as an alternative to Certificate Revocation Lists (CRLs), specifically addressing the overhead and latency issues of downloading large CRL files periodically.

Answer

CT logs

Answer

Certificate pinning

Answer

CRL distribution points

Question 2

A financial institution is implementing a Clark-Wilson integrity model. Which THREE components are essential to this model?

Accepted Answer

Constrained Data Items (CDIs). The Clark-Wilson integrity model relies on three core internal components to maintain data integrity: Constrained Data Items (CDIs), which are the protected data objects; Transformation Procedures (TPs), which are well-formed transactions that modify CDIs; and Integrity Verification Procedures (IVPs), which verify that CDIs are in a valid state. Unconstrained Data Items (UDIs) represent external, untrusted data that is not subject to the model's integrity controls until it is processed by a TP. User roles/subjects are part of the access triple (Subject, TP, CDI) but are not themselves one of the core data/procedure components of the model.

Answer

User roles

Answer

Unconstrained Data Items (UDIs)

Question 3

In the context of the Clark-Wilson integrity model, which of the following are key elements? (Choose TWO)

Accepted Answer

Constrained Data Items (CDIs). The Clark-Wilson integrity model is designed for commercial applications and focuses on preventing unauthorized modification of data. Its key components include Constrained Data Items (CDIs) (data whose integrity is protected), Unconstrained Data Items (UDIs) (unprotected data), Transformation Procedures (TPs) (well-formed transactions that transition CDIs from one valid state to another), and Integrity Verification Procedures (IVPs) (which confirm that CDIs are in a valid state).

Answer

Simple Security Property

Answer

Lattice-based access control

Answer

No Write Up property

Question 4

A security architect is designing a system for a military intelligence agency where data classification labels (Top Secret, Secret, Confidential, Unclassified) are mandatory. Users are cleared to a specific level and must not read data above their clearance. Which security model enforces this type of access control?

Accepted Answer

Bell-LaPadula model. Bell-LaPadula focuses on confidentiality and enforces no read up (simple security property) and no write down (*-property), matching the scenario's need to prevent reading higher classified data.

Answer

Biba model

Answer

Brewer-Nash model

Answer

Clark-Wilson model

Question 5

A financial application requires strict integrity controls to prevent unauthorized modifications. The security team implements a model where users cannot write data to higher integrity levels (no write up) and cannot read data from lower integrity levels (no read down). Which model is being applied?

Accepted Answer

Biba. Biba model enforces integrity: no write up (subjects cannot write to higher integrity objects) and no read down (subjects cannot read lower integrity data).

Answer

Bell-LaPadula

Answer

Graham-Denning

Answer

Clark-Wilson

Question 6

Which access control model allows data owners to grant or revoke access to resources they own, typically implemented using ACLs?

Accepted Answer

DAC. DAC (Discretionary Access Control) enables owners to control access to their resources, commonly via ACLs.

Answer

MAC

Answer

RBAC

Answer

ABAC

Question 7

A security architect is selecting a cryptographic algorithm for encrypting data at rest in a backup system. The system requires strong security with a block cipher, and the organization mandates using a NIST-approved algorithm with key sizes of 128, 192, or 256 bits. Which algorithm should be selected?

Accepted Answer

AES. AES is a NIST-approved symmetric block cipher supporting 128, 192, and 256-bit keys. It is the standard for data at rest encryption.

Answer

RC4

Answer

RSA

Answer

3DES

Question 8

A security engineer is analyzing a vulnerability where an attacker can cause a buffer overflow on the stack. Which mitigation technique randomizes memory addresses to make it harder for the attacker to predict the location of shellcode or return addresses?

Accepted Answer

ASLR. ASLR (Address Space Layout Randomization) randomizes the base addresses of stack, heap, and libraries, making it difficult for an attacker to guess memory addresses.

Answer

SafeSEH

Answer

Stack canaries

Answer

DEP/NX bit

Question 9

Which of the following is a primary function of a Trusted Platform Module (TPM)?

Accepted Answer

Storing cryptographic keys securely. A TPM provides hardware-based secure storage for cryptographic keys, enabling secure boot and remote attestation.

Answer

Encrypting network traffic

Answer

Providing antivirus protection

Answer

Enforcing access control policies

Question 10

A security architect is evaluating hypervisor security for a multi-tenant cloud environment. Which type of hypervisor is considered more secure because it runs directly on the hardware without a host operating system, reducing the attack surface?

Accepted Answer

Type 1 hypervisor. Type 1 hypervisors (bare-metal) run directly on hardware, eliminating the OS layer that could be exploited. Examples: VMware ESXi, Hyper-V.

Answer

Virtual machine monitor

Answer

Containers

Answer

Type 2 hypervisor

Question 11

Which physical security design principle emphasizes that the physical environment should be designed to discourage criminal activity by using natural surveillance, access control, and territorial reinforcement?

Accepted Answer

CPTED. CPTED (Crime Prevention Through Environmental Design) uses architectural features to reduce crime.

Answer

TEMPEST

Answer

Fail-safe

Answer

Layered defense

Question 12

A security analyst discovers that an application allows a user to read a file they just wrote before the file's integrity is verified, due to a gap between the time of check and time of use. This is an example of which vulnerability?

Accepted Answer

TOCTOU. TOCTOU (Time of Check to Time of Use) is a race condition where a resource is checked and then used, but the state changes in between.

Answer

Covert channel

Answer

Buffer overflow

Answer

Side-channel attack

Question 13

A security architect is designing a system that must prevent conflicts of interest when a consultant works for two competing clients. Which security model ensures that the consultant cannot access data from one client if they have already accessed data from the other?

Accepted Answer

Brewer-Nash. Brewer-Nash (Chinese Wall) model prevents conflict of interest by dynamically adjusting access based on previously accessed datasets.

Answer

Clark-Wilson

Answer

Biba

Answer

Bell-LaPadula

Question 14

Which component of a trusted computing base (TCB) implements the reference monitor concept by enforcing access control decisions for all subjects and objects in the system?

Accepted Answer

Security kernel. The security kernel is the part of the TCB that implements the reference monitor, mediating all access requests.

Answer

Trusted platform module

Answer

Trusted computing base

Answer

Reference monitor

Question 15

A security architect is evaluating access control models for a healthcare system where users have specific roles (e.g., doctor, nurse, admin) and permissions are assigned based on those roles. However, the architect also wants to incorporate attributes such as time of day, patient consent status, and device type. Which TWO models should be combined to meet these requirements?

Accepted Answer

ABAC. RBAC provides role-based permissions, while ABAC adds flexibility with attributes. Combining them allows fine-grained control.

Answer

Clark-Wilson

Answer

MAC

Answer

DAC

Question 16

A security engineer is investigating a covert channel in a system. Which TWO types of covert channels could be used to leak information from a high-security to a low-security process?

Accepted Answer

Covert timing channel. Covert timing channels modulate the timing of events to signal information. Covert storage channels write data to a shared resource that the other process can read.

Answer

TOCTOU

Answer

Emanations

Answer

Side-channel

Question 17

An organization is implementing a defense-in-depth strategy for a data center. Which THREE of the following are examples of physical security controls that align with layered defense?

Accepted Answer

Card reader at building entrance. Layered physical security includes perimeter fencing, building access controls (e.g., card readers), and internal secure areas (e.g., server cages).

Answer

Antivirus software

Answer

Intrusion detection system on the network

Question 18

A government agency requires a security model that prevents users from reading documents at a higher classification level and from writing to documents at a lower classification level. Which model enforces these constraints?

Accepted Answer

Bell-LaPadula. Bell-LaPadula enforces no read up (simple security property) and no write down (*-property) to ensure confidentiality.

Answer

Brewer-Nash

Answer

Clark-Wilson

Answer

Biba

Question 19

An organization implements a security model where users can only read objects at or below their security clearance, and can only write to objects at or above their clearance. This model primarily ensures:

Accepted Answer

Confidentiality. The described model is the Bell-LaPadula model, which enforces confidentiality. In Bell-LaPadula, subjects can read objects at or below their security level (read down) and write to objects at or above their level (write up). This prevents unauthorized access to higher classified information, ensuring confidentiality.

Answer

Integrity

Answer

Accountability

Answer

Availability

Question 20

A financial institution must ensure that transactions are well-formed and enforce separation of duties to prevent fraud. Which security model best addresses these requirements?

Accepted Answer

Clark-Wilson. Clark-Wilson model defines well-formed transactions and separation of duties to maintain commercial integrity.

Answer

Biba

Answer

Brewer-Nash

Answer

Bell-LaPadula