SCS-C02: AWS Certified Security - Specialty

The correct combination of steps that the security engineer should take to meet these requirements are A. Ensure that the Amazon CloudWatch agent is installed on all the EC2 instances that the Auto Scaling groups launch. Generate a CloudWatch agent configuration file to forward the required logs to Amazon CloudWatch Logs., B. Set the log retention for desired log groups to 7 years., and C. Attach an IAM role to the launch configuration or launch template that the Auto Scaling groups use. Configure the role to provide the necessary permissions to forward logs to Amazon CloudWatch Logs.

A) This answer is correct because it meets the requirement of ensuring that no logging data is lost for each instance during scaling activities. By installing the CloudWatch agent on all the EC2 instances, the security engineer can collect and send system logs and application logs to CloudWatch Logs, which is a service that stores and monitors log data. By generating a CloudWatch agent configuration file, the security engineer can specify which logs to forward and how often.

B) This answer is correct because it meets the requirement of keeping the logs for only the required period of 7 years. By setting the log retention for desired log groups, the security engineer can control how long CloudWatch Logs retains log events before deleting them. The security engineer can choose a predefined retention period of 7 years, or use a custom value.

C) This answer is correct because it meets the requirement of providing the necessary permissions to forward logs to CloudWatch Logs. By attaching an IAM role to the launch configuration or launch template that the Auto Scaling groups use, the security engineer can grant permissions to the EC2 instances that are launched by the Auto Scaling groups. By configuring the role to provide the necessary permissions, such as cloudwatch:PutLogEvents and cloudwatch:CreateLogStream, the security engineer can allow the EC2 instances to send log data to CloudWatch Logs.

this is the accurate reflection of the access control mechanisms that the Architect should verify. Access control mechanisms are methods that regulate who can access what resources and how. Security groups and network ACLs are two types of access control mechanisms that can be applied to EC2 instances and subnets. Security groups are stateful, meaning they remember and return traffic that was previously allowed. Network ACLs are stateless, meaning they do not remember or return traffic that was previously allowed. Security groups and network ACLs can have inbound and outbound rules that specify the source, destination, protocol, and port of the traffic. By verifying the outbound security group configuration on database servers, the inbound security group configuration on application servers, and the inbound and outbound network ACL configuration on both the database and application server subnets, the Architect can check if there are any misconfigurations or conflicts that prevent the application servers from initiating a connection to the database servers. The other options are either inaccurate or incomplete for verifying the access control mechanisms.

To implement the solution, the security engineer should do the following:

Assign an Elastic IP address to Amazon EFS and add the Elastic IP address to the allow list for the data center firewall. This allows the security engineer to use a specific IP address for the EFS file system that can be added to the firewall rules, instead of a CIDR range or a URL.

Install the AWS CLI on the data center-based servers to mount the EFS file system. This allows the security engineer to use the mount helper provided by AWS CLI to mount the EFS file system with encryption in transit.

In the EFS security group, add the IP addresses of the data center servers to the allow list. This allows the security engineer to restrict access to the EFS file system to only certain data center-based servers.

Mount the EFS using the Elastic IP address. This allows the security engineer to use the Elastic IP address as the DNS name for mounting the EFS file system.

The correct answer is C. Configure Route 53 Resolver query logging on all relevant VPCs. Send the logs to Amazon CloudWatch Logs. Use CloudWatch Insights to run queries on the source IP address and DNS name.

According to the AWS documentation1, Route 53 Resolver query logging lets you log the DNS queries that Route 53 Resolver handles for your VPCs. You can send the logs to CloudWatch Logs, Amazon S3, or Kinesis Data Firehose. The logs include information such as the following:

The AWS Region where the VPC was created

The ID of the VPC that the query originated from

The IP address of the instance that the query originated from

The instance ID of the resource that the query originated from

The date and time that the query was first made

The DNS name requested (such as prod.example.com)

The DNS record type (such as A or AAAA)

The DNS response code, such as NoError or ServFail

The DNS response data, such as the IP address that is returned in response to the DNS query

You can use CloudWatch Insights to run queries on your log data and analyze the results using graphs and statistics2. You can filter and aggregate the log data based on any field, and use operators and functions to perform calculations and transformations. For example, you can use CloudWatch Insights to find out how many queries were made for a specific domain name, or which instances made the most queries.

Therefore, this solution meets the requirements of logging and querying DNS traffic that goes to the on-premises DNS servers, showing details of the source IP address of the instance from which the query originated, and the DNS name that was requested in Route 53 Resolver.

The other options are incorrect because:

A) Using VPC Traffic Mirroring would not capture the DNS queries that go to the on-premises DNS servers, because Traffic Mirroring only copies network traffic from an elastic network interface of an EC2 instance to a target for analysis3. Traffic Mirroring does not include traffic that goes through a Route 53 Resolver outbound endpoint, which is used to forward queries to on-premises DNS servers4. Therefore, this solution would not meet the requirements.

B) Configuring VPC flow logs on all relevant VPCs would not capture the DNS name that was requested in Route 53 Resolver, because flow logs only record information about the IP traffic going to and from network interfaces in a VPC5. Flow logs do not include any information about the content or payload of a packet, such as a DNS query or response. Therefore, this solution would not meet the requirements.

D) Modifying the Route 53 Resolver rules on the authoritative domains that forward to the on-premises DNS servers would not enable logging of DNS queries, because Resolver rules only specify how to forward queries for specified domain names to your network6. Resolver rules do not have any logging functionality by themselves. Therefore, this solution would not meet the requirements.

1: Resolver query logging - Amazon Route 53 2: Analyzing log data with CloudWatch Logs Insights - Amazon CloudWatch 3: What is Traffic Mirroring? - Amazon Virtual Private Cloud 4: Outbound Resolver endpoints - Amazon Route 53 5: Logging IP traffic using VPC Flow Logs - Amazon Virtual Private Cloud 6: Managing forwarding rules - Amazon Route 53

The correct answer is D.

To stop the data exfiltration from the compromised EC2 instances, the security engineer needs to implement a solution that can deny access to any S3 bucket that is outside the company's organization. The solution should also allow the EC2 instances to access the required S3 buckets within the company's organization for the analysis process.

Option A is incorrect because updating the policy on the S3 gateway endpoint will not affect the access to S3 buckets that are outside the company's organization. The S3 gateway endpoint only applies to S3 buckets that are in the same AWS Region as the VPC. The compromised EC2 instances can still access S3 buckets in other Regions or other AWS accounts through the internet gateway or NAT device.

Option B is incorrect because updating the policy on the instance profile role will not prevent the compromised EC2 instances from using other credentials or methods to access S3 buckets outside the company's organization. The instance profile role only applies to requests that are made using the credentials of that role. The compromised EC2 instances can still use other IAM users, roles, or access keys to access S3 buckets outside the company's organization.

Option C is incorrect because adding a network ACL rule to block outgoing connections on port 443 will also block legitimate connections to S3 buckets within the company's organization. The network ACL rule will prevent the EC2 instances from accessing any S3 bucket through HTTPS, regardless of whether it is inside or outside the company's organization.

Option D is correct because applying an SCP on the AWS account will effectively deny access to any S3 bucket that is outside the company's organization. The SCP will apply to all IAM users, roles, and resources in the AWS account, regardless of how they access S3. The SCP will use the aws:ResourceOrgID and aws:PrincipalOrgID condition keys to check whether the S3 bucket and the principal belong to the same organization as the AWS account. If they do not match, the SCP will deny the S3 actions.

Using service control policies

AWS Organizations service control policy examples

The correct answer is D.

To implement short-term credentials for third-party AWS accounts, you can use IAM roles and trust policies. A trust policy is a JSON policy document that defines who can assume the role. You can specify the AWS account ID of the third-party account as a principal in the trust policy, and use the sts:ExternalId condition key to enhance the security of the role. The sts:ExternalId condition key is a unique identifier that is agreed upon by both parties and included in the AssumeRole request. This way, you can prevent the ''confused deputy'' problem, where an unauthorized party can use the same role as a legitimate party.

Option A is incorrect because bearer token authentication with OAuth or SAML is not suitable for granting access to AWS accounts and resources. Amazon Cognito and API Gateway are used for building web and mobile applications that require user authentication and authorization.

Option B is incorrect because AWS IAM Identity Center (AWS Single Sign-On) is a service that simplifies the management of access to multiple AWS accounts and cloud applications for your workforce users. It does not support granting access to third-party AWS accounts.

Option C is incorrect because using AWS Secrets Manager to create a random external key is not necessary and adds operational complexity. You can use the sts:ExternalId condition key instead to provide a unique identifier for each external account.