Assuming roles for temporary access in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main purpose of assuming a role in AWS?

Assuming a role allows a user or service to temporarily gain permissions defined by that role, enabling secure and controlled access without sharing long-term credentials.

beginner

What AWS service is commonly used to assume roles for temporary credentials?

AWS Security Token Service (STS) is used to assume roles and provide temporary security credentials.

intermediate

What is the maximum duration for temporary credentials when assuming a role using AWS STS?

The maximum duration is 12 hours by default, but it can be shorter or longer (up to 12 hours) depending on the role's session duration setting.

intermediate

How does assuming a role improve security compared to using long-term IAM user credentials?

It reduces risk by limiting the time credentials are valid and avoids sharing permanent access keys, making it easier to manage and revoke access.

beginner

What is a trust policy in the context of AWS roles?

A trust policy defines which entities (users, services, accounts) are allowed to assume the role.

Which AWS service provides temporary credentials when assuming a role?

A Amazon S3

B AWS Identity and Access Management (IAM)

C AWS CloudTrail

D AWS Security Token Service (STS)

AWS STS issues temporary credentials when you assume a role.

What is the maximum default session duration for an assumed role?

A 12 hours

B 1 hour

C 24 hours

D 7 days

The maximum session duration for an assumed role is 12 hours by default.

What does a trust policy specify in an IAM role?

A Which entities can assume the role

B Which actions the role can perform

C The password policy for users

D The billing details for the account

A trust policy defines who can assume the role.

Why is assuming roles preferred over sharing long-term IAM user credentials?

A Because roles have unlimited access

B Because roles do not require permissions

C Because temporary credentials reduce security risks

D Because IAM users cannot access AWS services

Temporary credentials limit exposure and reduce security risks.

Which of the following is NOT a benefit of using temporary credentials from assuming roles?

A No need to rotate long-term access keys

B Permanent access without expiration

C Automatic expiration of credentials

D Fine-grained access control

Temporary credentials expire and do not provide permanent access.

Explain how assuming roles works in AWS and why it is useful for temporary access.

Think about how you can get short-term permissions without sharing passwords.

Describe the role of a trust policy in the process of assuming a role.

It controls who is trusted to use the role.

Practice

1. What is the main benefit of assuming an AWS role for temporary access?

easy

A. It automatically deletes the AWS account after use.

B. It provides temporary, limited access without using permanent credentials.

C. It disables all access to AWS resources.

D. It creates a new permanent user with full permissions.

Solution

1. Step 1: Understand role assumption purpose

   Assuming a role grants temporary permissions without needing permanent credentials.

2. Step 2: Compare options

   Only 'It provides temporary, limited access without using permanent credentials.' correctly describes temporary, limited access. Others describe incorrect or unrelated actions.

3. Final Answer:

   It provides temporary, limited access without using permanent credentials. -> Option B

4. Quick Check:

   Temporary access = It provides temporary, limited access without using permanent credentials. [OK]

Hint: Temporary access means no permanent keys used [OK]

Common Mistakes:

• Thinking roles create permanent users
• Confusing role assumption with account deletion
• Believing role assumption disables access

2. Which AWS CLI command is used to assume a role for temporary access?

easy

A. aws sts assume-role

B. aws iam create-role

C. aws s3 ls

D. aws ec2 start-instances

Solution

1. Step 1: Identify the correct command for role assumption

   The AWS CLI command to assume a role is aws sts assume-role.

2. Step 2: Eliminate unrelated commands

   Commands like aws iam create-role create roles but do not assume them; others manage services unrelated to role assumption.

3. Final Answer:

   aws sts assume-role -> Option A

4. Quick Check:

   Assume role command = aws sts assume-role [OK]

Hint: Assume role uses 'sts' service in CLI [OK]

Common Mistakes:

• Using 'iam create-role' instead of 'sts assume-role'
• Confusing service commands like s3 or ec2
• Typing incorrect command syntax

3. What is the expected output when running this command?

aws sts assume-role --role-arn arn:aws:iam::123456789012:role/demo --role-session-name testSession

medium

A. A JSON with temporary security credentials including AccessKeyId, SecretAccessKey, and SessionToken.

B. An error saying 'role not found' because the ARN is invalid.

C. A list of all IAM users in the account.

D. A confirmation message that the role was created.

Solution

1. Step 1: Understand the command output

   The aws sts assume-role command returns temporary credentials in JSON format.

2. Step 2: Analyze options

   Only 'A JSON with temporary security credentials including AccessKeyId, SecretAccessKey, and SessionToken.' correctly describes the expected JSON output with temporary keys. Others describe errors or unrelated outputs.

3. Final Answer:

   A JSON with temporary security credentials including AccessKeyId, SecretAccessKey, and SessionToken. -> Option A

4. Quick Check:

   Assume-role output = temporary credentials JSON [OK]

Hint: Assume-role returns temporary keys in JSON [OK]

Common Mistakes:

• Expecting role creation confirmation instead of credentials
• Confusing assume-role output with user listing
• Assuming error without verifying ARN

4. You run aws sts assume-role but get an 'AccessDenied' error. What is the most likely cause?

medium

A. The AWS CLI is not installed on your machine.

B. The AWS account is suspended.

C. The role session name is missing from the command.

D. The IAM user or role does not have permission to assume the specified role.

Solution

1. Step 1: Understand 'AccessDenied' meaning

   This error means the caller lacks permission to perform the action.

2. Step 2: Identify permission requirements for assume-role

   The IAM user or role must have explicit permission to assume the target role.

3. Final Answer:

   The IAM user or role does not have permission to assume the specified role. -> Option D

4. Quick Check:

   AccessDenied = missing assume-role permission [OK]

Hint: AccessDenied usually means missing assume-role permission [OK]

Common Mistakes:

• Assuming CLI installation causes AccessDenied
• Ignoring required role session name
• Blaming account suspension without checking permissions

5. You want to allow an EC2 instance to assume a role temporarily to access S3 buckets. Which combination is correct?

hard

A. Manually run aws sts assume-role on the EC2 instance without any IAM role attached.

B. Create an IAM user with S3 permissions and store its permanent keys on the EC2 instance.

C. Attach an IAM role with S3 permissions to the EC2 instance and use the instance profile to assume the role automatically.

D. Attach a security group to the EC2 instance that allows S3 access.

Solution

1. Step 1: Understand EC2 role usage

   Attaching an IAM role to EC2 via instance profile allows automatic temporary credentials for S3 access.

2. Step 2: Evaluate other options

   Manually running aws sts assume-role without an attached IAM role fails due to lack of initial credentials. Using permanent IAM user keys is less secure. Security groups control network access, not IAM permissions.

3. Final Answer:

   Attach an IAM role with S3 permissions to the EC2 instance and use the instance profile to assume the role automatically. -> Option C

4. Quick Check:

   EC2 uses instance profile role for temporary access [OK]

Hint: Use instance profile roles for EC2 temporary access [OK]

Common Mistakes:

• Using permanent keys on EC2 instead of roles
• Trying to assume role without attached IAM role
• Confusing security groups with permissions