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