SCS-C02 Identity and Access Management — Timed 100 Questions

Question 1

A developer needs to grant an IAM user read-only access to an S3 bucket named 'my-bucket'. Which policy should be attached to the IAM user?

Accepted Answer

{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":"s3:GetObject","Resource":"arn:aws:s3:::my-bucket/*"}]}. Option D is correct because it grants the s3:GetObject permission on the 'my-bucket/*' resource, which allows the IAM user to read (download) objects from the bucket. For read-only access, the user needs both s3:ListBucket (to list objects) and s3:GetObject (to retrieve objects), but the question asks for a policy that grants read-only access; while D alone is insufficient for full read-only access (it lacks ListBucket), it is the only option that provides a read action on the bucket's objects. The other options either grant write access, full access, or only list permissions without read capability.

Answer

{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":"s3:ListBucket","Resource":"arn:aws:s3:::my-bucket"}]}

Answer

{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":"s3:*","Resource":"*"}]}

Answer

{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":"s3:PutObject","Resource":"arn:aws:s3:::my-bucket/*"}]}

Question 2

A security engineer notices that an IAM role has a trust policy allowing any AWS account to assume it. Which attack is this misconfiguration most likely to enable?

Accepted Answer

Unauthorized access by an external attacker. Option C is correct because an IAM role trust policy that allows any AWS account (i.e., `"Principal": {"AWS": "*"}`) to assume the role means that any user or service in any AWS account can call the STS `AssumeRole` API to obtain temporary credentials for the role. This directly enables unauthorized access by an external attacker who can discover the role ARN and assume it, gaining all permissions attached to the role.

Answer

Logging bypass via CloudTrail

Answer

Cross-service confused deputy attack

Answer

Privilege escalation by attaching additional policies

Question 3

An IAM policy includes the following condition: "StringNotEquals": {"aws:SourceArn": "arn:aws:ec2:us-east-1:123456789012:instance/*"}. What is the effect of this condition when attached to an IAM role?

Accepted Answer

Denies requests that do not originate from an EC2 instance in the specified account and region. The condition uses `StringNotEquals` with `aws:SourceArn`, meaning it denies access when the source ARN does NOT match the specified pattern. Since the condition is attached to a role's trust policy, it restricts which principals can assume the role. The correct effect is that requests not originating from an EC2 instance in account 123456789012 and region us-east-1 are denied.

Answer

Denies all requests from EC2 instances

Answer

Allows the role to be assumed only by EC2 instances in the specified account and region

Answer

Allows any request that comes from an EC2 instance regardless of account

Question 4

An IAM user receives an 'AccessDenied' error when trying to list objects in an S3 bucket. The user has the following policy attached: {"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":"s3:ListBucket","Resource":"arn:aws:s3:::example-bucket"}]}. What is the most likely reason?

Accepted Answer

The bucket policy explicitly denies the action. The IAM policy grants the s3:ListBucket action on the bucket, which should allow listing objects. However, an explicit deny in a bucket policy overrides any allow, including those from IAM policies. Since the user receives an 'AccessDenied' error, the most likely cause is that the bucket policy explicitly denies the s3:ListBucket action for this user, as explicit denies take precedence over all allows.

Answer

The policy is missing a condition

Answer

The policy does not include s3:GetObject

Answer

The policy has a syntax error

Question 5

A company wants to allow users from its corporate Active Directory to access AWS resources. The company has set up an IAM identity provider for SAML. What must be created in IAM to map users to permissions?

Accepted Answer

An IAM role with a trust policy for the SAML provider. A is correct because when using SAML-based federation, IAM roles are the mechanism to grant permissions to federated users. The role must have a trust policy that specifies the SAML identity provider as the principal, allowing users authenticated by the corporate Active Directory to assume the role and obtain temporary AWS credentials. This maps the SAML assertion attributes (such as the user's group or role) to IAM permissions via the role's permissions policy.

Answer

An OIDC identity provider

Answer

An IAM user for each Active Directory user

Answer

A federation role type

Question 6

An IAM policy has the following statement: {"Effect":"Deny","Action":"*","Resource":"*","Condition":{"Bool":{"aws:SecureTransport":"false"}}}. What does this policy achieve?

Accepted Answer

Denies all actions that are not made over HTTPS. This policy statement uses the `aws:SecureTransport` condition key with a `Bool` condition set to `false`. When the condition evaluates to true (i.e., the request is not using HTTPS/TLS), the `Deny` effect applies to all actions on all resources. This effectively denies any API call made over HTTP (non-secure transport), ensuring that only HTTPS requests are allowed. The policy does not explicitly allow anything; it only denies non-HTTPS traffic, so all actions are implicitly allowed when made over HTTPS.

Answer

Allows all actions only when using HTTPS

Answer

Enforces HTTPS for S3 bucket policies only

Answer

Blocks all actions for a specific AWS service

Question 7

A solutions architect needs to design a system where an EC2 instance can write logs to CloudWatch Logs. Which IAM entity should be used to grant permissions to the EC2 instance?

Accepted Answer

An IAM role with an instance profile. An IAM role with an instance profile is the correct approach because it allows the EC2 instance to assume temporary, rotated credentials via the AWS Security Token Service (STS). The instance profile is attached to the EC2 instance, and the AWS SDK or CLI automatically retrieves credentials from the instance metadata service (IMDS) to authenticate API calls to CloudWatch Logs. This eliminates the need to store long-term credentials on the instance and follows the principle of least privilege.

Answer

A resource-based policy on the EC2 instance

Answer

An IAM user with access keys stored on the instance

Answer

An IAM group

Question 8

A security administrator discovers that an IAM user has been deleted accidentally. What is the correct way to restore the user's access?

Accepted Answer

Create a new IAM user with the same name and attach the same policies. Option D is correct because IAM does not support undeletion or restoration of deleted users. When an IAM user is deleted, all associated credentials, permissions, and metadata are permanently removed. The only way to restore access is to create a new IAM user with the same name and manually reattach the same policies, groups, and tags, and then regenerate access keys and passwords as needed.

Answer

Contact AWS Support to undo the deletion

Answer

Use the AWS IAM console to undelete the user

Answer

Restore the user from a backup of IAM

Question 9

Which TWO actions can be performed using AWS IAM? (Choose two.)

Accepted Answer

Define a password policy for IAM users. Option C is correct because AWS IAM allows you to define a password policy for IAM users, which enforces complexity requirements, rotation periods, and reuse prevention. This is a core IAM feature that helps secure user credentials without relying on external identity providers.

Answer

Change the instance type of an RDS database

Answer

Create a CloudFront distribution

Answer

Configure a VPC peering connection

Question 10

Which THREE factors should be considered when designing IAM policies for cross-account access? (Choose three.)

Accepted Answer

The resource-based policy must allow the external account. Option A is correct because for cross-account access using resource-based policies (e.g., S3 bucket policies, KMS key policies), the resource-based policy must explicitly grant access to the external AWS account. This allows the external account's IAM principals to access the resource, provided the external account's IAM policy also permits the action. Without this allowance in the resource-based policy, the external account cannot access the resource, even if its own IAM policies allow it.

Answer

Permission boundaries must be used

Answer

Service control policies (SCPs) must allow the action

Question 11

Which TWO are valid ways to authenticate to AWS for API calls? (Choose two.)

Accepted Answer

IAM user access keys. IAM user access keys (option B) are a valid authentication method for programmatic API calls to AWS. They consist of an access key ID and a secret access key, which are used to sign requests using Signature Version 4 (SigV4). This is a standard, long-term credential for IAM users to interact with AWS services via CLI, SDK, or direct API calls.

Answer

SSH key pairs

Answer

Database master password

Answer

Root user access keys

Question 12

Refer to the exhibit. An IAM policy is attached to a group. An IAM user in that group attempts to stop an EC2 instance from IP address 198.51.100.10. What will happen?

Accepted Answer

The action is denied because the source IP does not match the allowed range. The IAM policy includes a `Deny` statement with a `NotIpAddress` condition that restricts all actions (including `StopInstances`) to the IP range `10.0.0.0/8`. Since the user's source IP is `198.51.100.10`, which falls outside this range, the deny statement explicitly blocks the action. In IAM, an explicit deny always overrides any allow, so the request is denied regardless of the allow statement in the first policy block.

Answer

The action is allowed because the first statement allows StopInstances

Answer

The action is allowed because the resource is '*'

Answer

The action is denied only if the user is not using MFA

Question 13

Refer to the exhibit. A security engineer runs the command above. Which of the following is true about the role MyRole?

Accepted Answer

The role can be assumed by EC2 instances. The command `aws ec2 associate-iam-instance-profile --instance-id i-1234567890abcdef0 --iam-instance-profile Name=MyRole` attaches an IAM instance profile to an EC2 instance. An instance profile is a container for an IAM role that enables EC2 instances to assume that role and obtain temporary credentials via the EC2 metadata service. Therefore, the role MyRole can be assumed by EC2 instances when associated through an instance profile.

Answer

The role has a resource-based policy attached

Answer

The role can be assumed by any IAM user in account 123456789012

Answer

The role can be assumed by any AWS service

Question 14

A company has a multi-account AWS Organization with three accounts: Management, Development, and Production. The Security team uses the Management account to manage IAM policies centrally. They have created a service control policy (SCP) named 'RestrictRootAccess' that denies all actions for the root user in all accounts. The SCP is attached to the root organizational unit. The Development account has an IAM role 'DevAdmin' with full administrator access via an IAM policy. The role's trust policy allows the Management account's 'SecurityAudit' role to assume it. A security engineer in the Management account assumes the 'SecurityAudit' role and then tries to assume the 'DevAdmin' role in the Development account. The assumption fails with an 'AccessDenied' error. What is the most likely cause?

Accepted Answer

The trust policy of the 'DevAdmin' role does not grant sts:AssumeRole to the 'SecurityAudit' role. The error 'AccessDenied' occurs because the trust policy of the 'DevAdmin' role in the Development account does not explicitly grant the 'sts:AssumeRole' action to the 'SecurityAudit' role from the Management account. Even though the 'SecurityAudit' role has permission to call sts:AssumeRole via its IAM policy, the target role's trust policy acts as a resource-based policy that must allow the incoming principal. Without that allow, the assumption fails regardless of permissions in the source account.

Answer

The SCP is attached to the root OU and overrides any allow in the member accounts

Answer

The SCP 'RestrictRootAccess' denies the sts:AssumeRole action for all principals except root

Answer

The 'SecurityAudit' role requires MFA to assume the 'DevAdmin' role

Question 15

A company uses AWS Organizations with multiple accounts. The security team wants to ensure that all IAM users in the production account must use multi-factor authentication (MFA) to access the AWS Management Console. Which combination of actions should the security team take to enforce this requirement?

Accepted Answer

Create an IAM policy that denies all console actions unless MFA is present. Attach the policy to the IAM group that contains all production users.. Option D is correct because an IAM policy with a condition that denies all console actions unless MFA is present can be attached to an IAM group containing all production users. This enforces MFA at the user level within the account, directly meeting the requirement to ensure all IAM users in the production account must use MFA to access the AWS Management Console.

Answer

Use an SCP to deny access to the AWS Management Console unless MFA is present. Attach the SCP to the production OU.

Answer

Disable password-based access for all IAM users and require federation with an identity provider that enforces MFA.

Answer

Enable MFA on the root user and apply a password policy that requires MFA.

Question 16

A developer is trying to upload an object to an S3 bucket named 'my-bucket' using the AWS CLI. The developer has an IAM user with a policy that includes 's3:PutObject' for 'arn:aws:s3:::my-bucket/*'. However, the upload fails with an 'Access Denied' error. The bucket policy is set to allow all principals from the same AWS account to perform 's3:PutObject'. What is the most likely cause of this failure?

Accepted Answer

The IAM policy grants 's3:PutObject' only on objects (/*), but the request may also require 's3:PutObject' on the bucket itself for some operations.. Option C is correct because the IAM policy grants 's3:PutObject' only on the bucket's object ARN (arn:aws:s3:::my-bucket/*), but certain S3 operations, such as multipart uploads initiated via the AWS CLI, may require the 's3:PutObject' permission on the bucket resource itself (arn:aws:s3:::my-bucket) to complete the upload. The bucket policy allows 's3:PutObject' for all principals in the same account, but the IAM user's policy is too restrictive, causing the 'Access Denied' error.

Answer

The IAM user is not authorized to perform 's3:PutObject' on the bucket 'my-bucket'.

Answer

The bucket policy denies access because the principal is not explicitly listed.

Answer

The bucket 'my-bucket' does not exist in the same region as the CLI request.

Question 17

A security administrator is designing a cross-account access strategy. The administrator needs to allow users in Account A to assume an IAM role in Account B to access an S3 bucket. Which TWO of the following statements are true regarding this configuration?

Accepted Answer

The IAM users in Account A must have an IAM policy that allows the sts:AssumeRole action for the role ARN in Account B.. Option A is correct because for an IAM user in Account A to assume a role in Account B, the user must be explicitly granted permission to call the sts:AssumeRole API action against the role's Amazon Resource Name (ARN). This is done by attaching an IAM policy to the user (or a group/role the user belongs to) that includes the sts:AssumeRole action and specifies the target role ARN as the resource. Without this permission, the user cannot initiate the cross-account role assumption, even if the role's trust policy allows it.

Answer

The trust policy for the role must be defined in Account A.

Answer

The S3 bucket policy must grant access to the IAM users in Account A.

Answer

The IAM users in Account A must have cross-account permissions on the S3 bucket in Account B.

Question 18

An IAM policy is attached to a user. The user is trying to change their own password in the IAM console but receives an 'Access Denied' error. The user has an MFA device configured and is logged in with MFA. Why is the password change failing?

Accepted Answer

The Deny statement uses 'BoolIfExists' which evaluates to true if the condition key is not present. In the IAM console, the 'aws:MultiFactorAuthPresent' key may not be set, causing the Deny to apply even when the user has MFA.. Option B is correct because the Deny statement uses the `BoolIfExists` condition operator with the `aws:MultiFactorAuthPresent` key. In the IAM console, the `aws:MultiFactorAuthPresent` key may not be present in the request context (e.g., during the initial password change flow before MFA is re-validated), causing `BoolIfExists` to evaluate to true when the key is absent. This triggers the Deny even though the user has an MFA device and is logged in with MFA, blocking the `iam:ChangePassword` action.

Answer

The Allow statement for iam:ChangePassword is not sufficient because the Deny statement explicitly denies all actions.

Answer

The Deny statement denies all actions unconditionally, so the Allow statement cannot override it.

Answer

The user does not have permission to change their own password because the Allow statement is not specific enough.

Question 19

A company has a single AWS account with multiple IAM users. The administrator created an IAM policy that allows all users to launch EC2 instances, but only if they use a specific AMI ID (ami-12345678) and a specific instance type (t3.micro). The policy uses a condition that checks the EC2 instance type and AMI ID. However, a user is able to launch an EC2 instance with a different AMI ID and a larger instance type. The administrator reviews the policy and confirms that the condition is correctly written. What is the most likely reason that the policy is not working as expected?

Accepted Answer

The condition keys used (ec2:InstanceType and ec2:ImageId) are not supported for the RunInstances action in IAM policies.. Option A is correct because the `ec2:InstanceType` and `ec2:ImageId` condition keys are not supported for the `ec2:RunInstances` action in IAM policies. AWS IAM condition keys for EC2 are action-specific, and for RunInstances, only certain keys like `ec2:InstanceType` and `ec2:ImageId` are actually supported in the request context. However, the key detail is that `ec2:ImageId` is not a valid condition key for RunInstances; the correct key is `ec2:ImageId` is not listed in the AWS documentation for RunInstances, meaning the condition is silently ignored, allowing any AMI and instance type.

Answer

The policy is attached to the user but must also be attached to the IAM group.

Answer

The policy does not include an explicit deny statement for non-compliant launches.

Answer

The condition is written incorrectly; it should use StringLike instead of StringEquals.

Question 20

A company has an S3 bucket policy that allows cross-account access for a specific IAM role in another account. The bucket policy includes a Principal element with the ARN of the role. However, users in the other account that assume the role are unable to access the bucket. Which of the following is the MOST likely cause?

Accepted Answer

The bucket policy uses the role ARN in the Principal element instead of the AWS account ID.. Option D is correct because when an S3 bucket policy uses a role ARN in the Principal element, the policy only grants access to that specific role session, not to the users who assume the role. Cross-account access via S3 bucket policies requires the Principal to be set to the AWS account ID (or a canonical user ID) of the other account, not the ARN of a role. The role ARN in the Principal element is not evaluated as a valid principal for S3 bucket policies in the same way as an account ID, causing the access to fail.

Answer

The IAM role does not have a permissions policy granting s3:GetObject on the bucket.

Answer

The bucket policy has an explicit Deny statement that overrides the Allow.

Answer

The role's trust policy does not allow the S3 service to assume the role.