|Latest Update with Complete Solution
66 66 66 66 66
VUN1 — VUN1 Task 1: Managing Security Operations and Access Controls
66 66 66 66 66 66 66 66 66 66
Information Systems Security - C845
66 66 66 66 66
A. Apply an Access Control Model 66 66 66 66
A.1. Chosen Access Control Model 66 66 66
I have chosen the Role-Based Access Control (RBAC) model. The principles of RBAC are:
66 66 66 66 66 66 66 66 66 66 66 66 66
• Role Assignment: A user is assigned to a role based on their job function (e.g., "Finance
66 66 66 66 66 66 66 66 66 66 66 66 66 66 66
Analyst").
66
• Permission Assignment: Permissions to perform operations on systems are assigned to roles,
66 66 66 66 66 66 66 66 66 66 66
not to individual users.
66 66 66 66
• Session Management: A user activates a role to gain the associated permissions for a session.
66 66 66 66 66 66 66 66 66 66 66 66 66 66
• Least Privilege: Users should only have the minimum level of access necessary to perform their
66 66 66 66 66 66 66 66 66 66 66 66 66 66
job duties.
66 66
The organization's access control structure, as seen in the user matrix, is implicitly role-based (e.g.,
66 66 66 66 66 66 66 66 66 66 66 66 66 66
"Finance manager," "HR coordinator"). Applying a formal RBAC model would streamline this by ensuring
66 66 66 66 66 66 66 66 66 66 66 66 66 66
permissions are strictly tied to business functions, reducing complexity and the potential for user error
66 66 66 66 66 66 66 66 66 66 66 66 66 66 66
when assigning permissions.
66 66 66
A.2. Four Misalignments with RBAC Principles 6 6 6 6 6 6 6 6
1. Misalignment 1: Privilege Escalation Beyond Role Scope 66 66 66 66 66 66
• Description: The "Junior system admin" (J. Lopez) has "Domain admin" privileges. A 66 66 66 66 66 66 66 66 66 66 66
junior role should not have the highest level of access in a Windows environment.
66 66 66 66 66 66 66 66 66 66 66 66 66 66
• Conflict with RBAC: This violates the principle of least privilege. The role "Junior system
66 66 66 66 66 66 66 66 66 66 66 66 66
admin" implies a subset of administrative duties, not unrestricted domain-wide control.
66 66 66 66 66 66 66 66 66 66 66
2. Misalignment 2: Unnecessary Access Across Departments 66 66 66 66 66
• Description: The "Finance analyst" (L. Cheng) has "Full access" to the CRM, a system 66 66 66 66 66 66 66 66 66 66 66 66 66
, primarily for Sales and Support. A finance role typically does not require full modification
66 66 66 66 66 66 66 66 66 66 66 66 66
rights in a customer relationship system.
66 66 66 66 66 66
• Conflict with RBAC: This violates least privilege and separation of duties. It allows for
66 66 66 66 66 66 66 66 66 66 66 66 66
potential data manipulation outside the user's core business function.
66 66 66 66 66 66 66 66 66
3. Misalignment 3: Violation of User-Role Assignment Post-Termination
66 66 66 66 66 66
• Description: The "HR assistant" (P. Ellis), who was terminated on 2025-05-20, has an
66 66 66 66 66 66 66 66 66 66 66 66
"Active" account status and successfully logged in on 2025-06-29.
66 66 66 66 66 66 66 66 66
• Conflict with RBAC: RBAC requires timely revocation of role assignments upon a change in
66 66 66 66 66 66 66 66 66 66 66 66 66
employment status. An active session for a terminated user completely bypasses the
66 66 66 66 66 66 66 66 66 66 66 66
security provided by the role structure.
66 66 66 66 66 66
4. Misalignment 4: Overly Broad Privileged Access
66 66 66 66 66
• Description: The "IT administrator" (T. Miller) has "Full admin" access to "All internal
66 66 66 66 66 66 66 66 66 66 66 66
systems," and the log shows they made a firewall rule change without a ticket_id.
66 66 66 66 66 66 66 66 66 66 66 66 66 66
• Conflictwith RBAC: While some access is necessary, blanket "Full admin" access
6 66 66 66 66 66 66 66 66 66 66
violates least privilege and impedes accountability. It does not segment duties within the IT
66 66 66 66 66 66 66 66 66 66 66 66 66
department itself.
66 66