Access control models (MAC, DAC, ABAC) in Cybersecurity - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Mandatory Access Control (MAC)

Which statement best describes how Mandatory Access Control (MAC) manages access permissions?

A Access decisions are based on labels assigned to users and resources, enforced by the system.

B Users can set access permissions on their own files and resources.

C Access is granted based on user roles and their assigned permissions.

D Access permissions are granted dynamically based on user attributes and environmental conditions.

💡 Hint

Think about who controls the access rules in MAC.

In Mandatory Access Control, the system enforces access based on security labels assigned to both users and resources. Users cannot change these permissions themselves.

📋 Factual

intermediate

Discretionary Access Control (DAC) Characteristics

Which of the following is a key characteristic of Discretionary Access Control (DAC)?

A Access is determined by matching user attributes to policies.

B Access rights are assigned by a central authority and cannot be changed by users.

C Users have the ability to grant or revoke access to resources they own.

D Access decisions are based on predefined security labels.

💡 Hint

Consider who controls permissions in DAC.

In DAC, the owner of a resource can decide who else can access it, allowing users to grant or revoke permissions.

🔍 Analysis

advanced

Comparing ABAC with DAC and MAC

Which feature uniquely distinguishes Attribute-Based Access Control (ABAC) from both DAC and MAC?

A Users can freely assign permissions to their resources.

B Access is granted based on evaluating multiple attributes of users, resources, and environment dynamically.

C Access permissions are static and cannot change during a session.

D Access decisions are based on fixed security labels assigned by the system.

💡 Hint

Think about how ABAC uses information beyond just ownership or labels.

ABAC evaluates various attributes such as user role, resource type, time of access, and location to make flexible access decisions.

❓ Reasoning

advanced

Identifying Access Control Model by Scenario

A company enforces access where only users with a security clearance level equal to or higher than the document's classification can view it. Users cannot change these permissions. Which access control model is this?

A Role-Based Access Control (RBAC)

B Attribute-Based Access Control (ABAC)

C Discretionary Access Control (DAC)

D Mandatory Access Control (MAC)

💡 Hint

Consider who controls the permissions and how they are enforced.

This scenario describes MAC, where access is controlled by system-enforced labels like security clearance and classification levels.

❓ Comparison

expert

Evaluating Access Control Models for Dynamic Environments

In a cloud environment where access must adapt to changing user roles, device security status, and time of day, which access control model is most suitable?

A Attribute-Based Access Control (ABAC)

B Mandatory Access Control (MAC)

C Discretionary Access Control (DAC)

D Role-Based Access Control (RBAC)

💡 Hint

Think about which model supports flexible, attribute-driven decisions.

ABAC supports dynamic access decisions based on multiple attributes like user role, device status, and time, making it ideal for cloud environments.

Practice

1. Which access control model uses labels and system-enforced rules to restrict access?

easy

A. Mandatory Access Control (MAC)

B. Discretionary Access Control (DAC)

C. Attribute-Based Access Control (ABAC)

D. Role-Based Access Control (RBAC)

Solution

1. Step 1: Understand MAC characteristics

   MAC uses labels and system rules to control access, not user choice.

2. Step 2: Compare with other models

   DAC lets owners decide, ABAC uses attributes, RBAC uses roles. Only MAC uses labels and system rules.

3. Final Answer:

   Mandatory Access Control (MAC) -> Option A

4. Quick Check:

   Labels + system rules = MAC [OK]

Hint: Labels and system rules mean MAC model [OK]

Common Mistakes:

• Confusing DAC with MAC because both control access
• Thinking ABAC uses labels like MAC
• Mixing RBAC roles with MAC labels

2. Which of the following correctly describes Discretionary Access Control (DAC)?

easy

A. Access is based on predefined roles within an organization

B. Access is controlled by system-enforced labels only

C. Access is granted based on user attributes like time and location

D. Resource owners decide who can access their resources

Solution

1. Step 1: Recall DAC definition

   DAC allows resource owners to decide who can access their resources.

2. Step 2: Eliminate other options

   System-enforced labels describe MAC, attributes describe ABAC, roles describe RBAC.

3. Final Answer:

   Resource owners decide who can access their resources -> Option D

4. Quick Check:

   Owner control = DAC [OK]

Hint: Owner decides access means DAC model [OK]

Common Mistakes:

• Confusing DAC with MAC which uses system labels
• Mixing ABAC attributes with DAC
• Assuming roles control DAC access

3. Consider this scenario: A system grants access to a file only if the user's department matches the file's department attribute and access time is within business hours. Which access control model is this an example of?

medium

A. Mandatory Access Control (MAC)

B. Discretionary Access Control (DAC)

C. Attribute-Based Access Control (ABAC)

D. Role-Based Access Control (RBAC)

Solution

1. Step 1: Identify key access factors

   Access depends on user attributes (department) and conditions (time).

2. Step 2: Match model to attribute-based rules

   ABAC uses attributes like department and time to decide access.

3. Final Answer:

   Attribute-Based Access Control (ABAC) -> Option C

4. Quick Check:

   Attributes + conditions = ABAC [OK]

Hint: Attributes and conditions point to ABAC model [OK]

Common Mistakes:

• Choosing MAC because of strict rules
• Confusing RBAC roles with attributes
• Thinking DAC controls by owner only

4. A company uses a system where users can share files and decide who else can access them, but the system also enforces security labels on files that cannot be changed by users. What is the error in this access control setup?

medium

A. It does not enforce any access control

B. It mixes DAC and MAC models incorrectly

C. It allows users to override system labels

D. It uses ABAC without defining attributes

Solution

1. Step 1: Analyze the setup

   Users control sharing (DAC), but system enforces labels (MAC).

2. Step 2: Identify conflict

   Mixing DAC and MAC can cause conflicts because MAC labels cannot be overridden by users.

3. Final Answer:

   It mixes DAC and MAC models incorrectly -> Option B

4. Quick Check:

   Mixing DAC and MAC causes conflicts [OK]

Hint: DAC owner control conflicts with MAC system labels [OK]

Common Mistakes:

• Assuming ABAC is used without attributes
• Thinking users can override MAC labels
• Ignoring the presence of enforced labels

5. An organization wants to implement an access control system that allows access based on user role, time of day, and location, but also requires that certain highly sensitive files can only be accessed by users with a specific security clearance label. Which combination of access control models best fits this requirement?

hard

A. Mandatory Access Control (MAC) combined with Attribute-Based Access Control (ABAC)

B. Discretionary Access Control (DAC) combined with Role-Based Access Control (RBAC)

C. Role-Based Access Control (RBAC) only

D. Attribute-Based Access Control (ABAC) only

Solution

1. Step 1: Identify requirements

   Access depends on role, time, location (attributes) and security clearance labels (system-enforced).

2. Step 2: Match models to requirements

   ABAC handles attributes like role, time, location; MAC enforces security clearance labels.

3. Step 3: Combine models for full coverage

   Using MAC with ABAC covers both label enforcement and attribute-based conditions.

4. Final Answer:

   Mandatory Access Control (MAC) combined with Attribute-Based Access Control (ABAC) -> Option A

5. Quick Check:

   Labels + attributes = MAC + ABAC [OK]

Hint: Combine MAC labels with ABAC attributes for complex control [OK]

Common Mistakes:

• Choosing RBAC only, missing label enforcement
• Using DAC which lacks system labels
• Assuming ABAC alone handles security labels