AWS Identity & Access Management: Mastering the Principle of Least Privilege

This curriculum overview provides a structured roadmap for mastering AWS Identity and Access Management (IAM). It focuses on the secure configuration of users, groups, and policies while adhering to industry-standard security principles.

Prerequisites

Before beginning this module, learners should have a foundational understanding of the following:

• Cloud Computing Basics: Understanding the shared responsibility model.
• AWS Account Basics: Knowledge of how to sign up for an AWS account and the initial purpose of the Root User.
• Basic JSON Syntax: Policies in AWS are written in JSON; familiarity with key-value pairs is essential.

Module Breakdown

Module Objectives

Module 1: The Foundation of Identity

• Secure the Root User: Learn why the root account (email login) should never be used for daily tasks.
• Credential Management: Configure strong password policies and enable Multi-Factor Authentication (MFA).

Module 2: Scaling with Groups

• Efficiency at Scale: Understand how to use IAM Groups to avoid the "tedious chore" of per-user permission assignment.
• Inheritance: Map how a user automatically inherits all permissions attached to their group.

Module 3: The Power of Policies

• Managed vs. Custom: Differentiate between AWS Managed Policies (created/maintained by AWS) and Customer Managed Policies (custom-built for specific needs).
• Least Privilege Execution: Practice writing policies that grant only the minimum required permissions.

Success Metrics

To demonstrate mastery of this curriculum, the learner must be able to:

1. Eliminate Root Usage: Show 0% usage of the root account for daily administrative tasks in AWS CloudTrail.
2. Policy Precision: Create a custom policy that allows s3:GetObject on a specific bucket without using the wildcard * character for actions or resources.
3. Audit Readiness: Generate an IAM Credential Report and identify any users who have not rotated passwords in >90 days.

Real-World Application

In a professional setting, these skills are critical for roles such as Cloud Security Engineer or DevOps Architect.

[!IMPORTANT] A "set and forget" mentality is the leading cause of cloud data breaches. Professionals use the Principle of Least Privilege (PoLP) to ensure that if a developer's credentials are stolen, the attacker can only access a tiny fraction of the infrastructure.

Examples & Scenarios

▶Click to expand: Scenario 1 - The Junior S3 Developer

Requirement: A new hire needs to read files from the company-logs bucket but should not be able to delete anything or see other buckets.

Implementation:

1. Create User: JuniorDev01.
2. Create Group: LogReaders.
3. Attach Policy:
   jsonCopy

   { "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Action": "s3:GetObject", "Resource": "arn:aws:s3:::company-logs/*" } ] }

Result: Complies with PoLP by restricting both the Action (read only) and the Resource (one bucket).

▶Click to expand: Scenario 2 - The EC2 Administrator

Requirement: An admin needs to start and stop EC2 instances but should not have permission to change billing or delete IAM users.

Implementation:

• Action: Use the AWS Managed Policy AmazonEC2FullAccess as a starting point.
• Refinement: If the admin only manages a specific project, create a Customer Managed Policy that filters by tags (e.g., Project: Alpha).

Summary of Key Terms