IAM Security tools and IAM Best Practice

AWS IAM: Roles, Security Tools & Best Practices

1. IAM Roles for AWS Services

IAM roles allow AWS services to securely interact with other AWS resources without hardcoding credentials.

Key Features:

• Temporary Credentials: Roles provide short-term credentials instead of long-term access keys.
• Service-Linked Roles: Predefined by AWS for services like EC2, Lambda, RDS, etc.
• Cross-Account Access: Enables secure access between different AWS accounts.

Common Use Cases:

• EC2 instances needing access to S3.
• Lambda functions interacting with DynamoDB.
• AWS Step Functions calling other AWS services.

Example:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": { "Service": "lambda.amazonaws.com" },
      "Action": "sts:AssumeRole"
    }
  ]
}

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2. IAM Security Tools

A. IAM Credentials Report

Generates a detailed report of all IAM users and their credentials (passwords, access keys, MFA status).

How to Generate:

aws iam generate-credential-report
aws iam get-credential-report --output text --query Content | base64 --decode > report.csv

Key Checks:
✔ Expired passwords/keys
✔ Unused access keys (>90 days old)
✔ Users without MFA

B. IAM Access Advisor

Shows service permissions granted to a user/role and when they were last accessed.

How to Use:

• Navigate to IAM → Users/Roles → Access Advisor.
• Identifies unused permissions for cleanup (least privilege principle).

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3. IAM Best Practices

A. Least Privilege Principle

• Grant only necessary permissions.
• Regularly review policies using Access Advisor.

B. Enable MFA (Multi-Factor Authentication)

• Required for root and privileged users.

C. Use IAM Roles Instead of Access Keys

• Avoid long-term access keys; prefer roles for AWS services.

D. Rotate Credentials Regularly

• Enforce password & access key rotation policies.

E. Monitor with AWS CloudTrail & AWS Config

• Track IAM changes and compliance.

F. Avoid Root Account Usage

• Use IAM users/roles for daily operations.

G. Use Policy Conditions

• Restrict access by IP, time, or MFA.

"Condition": {
  "IpAddress": {"aws:SourceIp": ["192.0.2.0/24"]},
  "Bool": {"aws:MultiFactorAuthPresent": "true"}
}

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Conclusion

• IAM Roles provide secure, temporary access for AWS services.
• Credentials Report & Access Advisor help audit and refine permissions.
• Best Practices ensure security, compliance, and least privilege access.