Why Least privilege principle in GCP? - Purpose & Use Cases

The Big Idea

What if one extra permission could let someone accidentally erase your entire cloud setup?

The Scenario

Imagine giving every employee in a company the master key to all rooms, including sensitive areas like the safe or CEO's office.

It sounds convenient but risky, right? In cloud systems, manually assigning broad access to users or services is just like that.

The Problem

Manually managing who can do what is slow and confusing.

People often get more access than needed, which can lead to accidental or harmful changes.

Tracking and fixing these mistakes takes a lot of time and can cause security breaches.

The Solution

The least privilege principle means giving users or services only the exact access they need, nothing more.

This keeps systems safer and easier to manage because permissions are clear and limited.

Before vs After

✗ Before

Assign role: Owner to all users

✓ After

Assign role: Storage Object Viewer only to user needing read access

What It Enables

It enables secure, simple, and controlled access that protects your cloud resources from mistakes and attacks.

Real Life Example

A developer only gets permission to deploy code but cannot delete databases, preventing accidental data loss.

Key Takeaways

Manual broad access is risky and hard to fix.

Least privilege limits access to what is truly needed.

This principle improves security and management in cloud environments.

Practice

1. What does the least privilege principle mean in cloud security?

easy

A. Grant access based on seniority, not tasks

B. Give all users full access to all resources

C. Allow users to share passwords for easier access

D. Give users only the access they need to do their job

Solution

1. Step 1: Understand the principle meaning

   Least privilege means limiting access rights to the minimum necessary for tasks.

2. Step 2: Match the correct description

   Give users only the access they need to do their job correctly states giving only needed access, while others give too much or irrelevant access.

3. Final Answer:

   Give users only the access they need to do their job -> Option D

4. Quick Check:

   Least privilege = minimal necessary access [OK]

Hint: Least privilege means minimal access needed only [OK]

Common Mistakes:

• Thinking least privilege means full access
• Confusing least privilege with password sharing
• Assuming access depends on seniority

2. Which of the following is the correct way to assign a role following the least privilege principle in GCP IAM?

easy

A. Assign a predefined role that only allows necessary actions

B. Assign the 'Owner' role to all users for easy management

C. Assign the 'Editor' role to everyone to avoid permission issues

D. Assign no roles and let users request access when needed

Solution

1. Step 1: Review role assignment options

   Least privilege requires giving only necessary permissions, not broad ones like Owner or Editor.

2. Step 2: Identify the best practice

   Predefined roles with limited permissions fit least privilege best, so Assign a predefined role that only allows necessary actions is correct.

3. Final Answer:

   Assign a predefined role that only allows necessary actions -> Option A

4. Quick Check:

   Least privilege = specific predefined roles [OK]

Hint: Use predefined roles with minimal permissions [OK]

Common Mistakes:

• Assigning Owner or Editor roles broadly
• Not using predefined roles
• Giving no roles and causing delays

3. Consider this IAM policy snippet in GCP:

{
  "bindings": [
    {
      "role": "roles/storage.objectViewer",
      "members": ["user:[e-mail]"]
    }
  ]
}

What access does Alice have?

medium

A. Full control over storage buckets

B. Can view objects in storage buckets

C. Can edit and delete storage objects

D. No access to storage resources

Solution

1. Step 1: Identify the role assigned

   The role is 'roles/storage.objectViewer', which allows viewing objects only.

2. Step 2: Understand permissions of the role

   This role grants read-only access to storage objects, no editing or deleting.

3. Final Answer:

   Can view objects in storage buckets -> Option B

4. Quick Check:

   objectViewer = read-only access [OK]

Hint: Viewer roles allow read-only access [OK]

Common Mistakes:

• Confusing viewer with editor or owner roles
• Assuming viewer can delete or edit
• Ignoring the specific role name

4. You assigned the 'roles/editor' role to a service account, but it only needs to read data. What is the best fix to follow the least privilege principle?

medium

A. Keep the 'editor' role since it covers all needs

B. Remove the role and do not assign any role

C. Change the role to 'roles/viewer' or a more specific read-only role

D. Assign the 'owner' role for future flexibility

Solution

1. Step 1: Identify the problem with current role

   'roles/editor' grants broad permissions beyond reading, violating least privilege.

2. Step 2: Choose a role with minimal needed permissions

   Assigning 'roles/viewer' or a specific read-only role limits access appropriately.

3. Final Answer:

   Change the role to 'roles/viewer' or a more specific read-only role -> Option C

4. Quick Check:

   Least privilege = minimal needed permissions [OK]

Hint: Use read-only roles if only reading is needed [OK]

Common Mistakes:

• Keeping overly broad roles
• Removing roles entirely causing access failure
• Assigning owner role unnecessarily

5. You manage a GCP project with multiple teams. One team needs to deploy apps but should not access billing info. How do you apply the least privilege principle?

hard

A. Assign a custom role with deployment permissions but no billing access

B. Assign 'Project Owner' role to the team for full control

C. Assign the 'Project Editor' role to the team and 'Billing Admin' to a few users

D. Give the team billing account access to avoid deployment delays

Solution

1. Step 1: Understand team needs and restrictions

   The team needs deployment rights but must not access billing info.

2. Step 2: Choose role assignment following least privilege

   A custom role with only deployment permissions and no billing access fits best.

3. Final Answer:

   Assign a custom role with deployment permissions but no billing access -> Option A

4. Quick Check:

   Least privilege = custom roles for precise access [OK]

Hint: Use custom roles to separate duties precisely [OK]

Common Mistakes:

• Giving broad roles like Owner or Editor
• Granting billing access unnecessarily
• Ignoring custom roles for fine control