Pipeline: 5.6 Ensure that EC2 Metadata Service only allows IMDSv2

Description

When enabling the Metadata Service on AWS EC2 instances, users have the option of using either Instance Metadata Service Version 1 (IMDSv1; a request/response method) or Instance Metadata Service Version 2 (IMDSv2; a session-oriented method).

Allowing Version 1 of the service may open EC2 instances to Server-Side Request Forgery (SSRF) attacks, so Amazon recommends utilizing Version 2 for better instance security.

Remediation

From Console:

Sign in to the AWS Management Console and navigate to the EC2 dashboard at (https://console.aws.amazon.com/ec2/)[https://console.aws.amazon.com/ec2/].
In the left navigation panel, under the INSTANCES section, choose Instances.
Select the EC2 instance that you want to examine.
Choose Actions > Instance Settings > Modify instance metadata options.
Ensure Instance metadata service is set to Enable and set IMDSv2 to Required.
Repeat steps no. 1 – 5 to perform the remediation process for other EC2 Instances in the all applicable AWS region(s).

From Command Line:

Run the describe-instances command using appropriate filtering to list the IDs of all the existing EC2 instances currently available in the selected region:

aws ec2 describe-instances --region <region-name> --output table --query "Reservations[*].Instances[*].InstanceId"

The command output should return a table with the requested instance IDs.
Now run the modify-instance-metadata-options command using an instance ID returned at the previous step to update the Instance Metadata Version:

aws ec2 modify-instance-metadata-options --instance-id <instance-id> --http-tokens required --region <region-name>

Repeat steps no. 1 – 3 to perform the remediation process for other EC2 Instances in the same AWS region.
Change the region by updating --region and repeat the entire process for other regions.

Run the pipeline

To run this pipeline from your terminal:

flowpipe pipeline run aws_cis.pipeline.cis_v300_5_6

Use this pipeline

To call this pipeline from your pipeline, use a step:

step "pipeline" "step_name" {
  pipeline = aws_cis.pipeline.cis_v300_5_6  
}

Params

Name	Type	Required	Description	Default
database	connection.steampipe	Yes	Database connection string.	`connection.steampipe.default`
notifier	notifier	Yes	The name of the notifier to use for sending notification messages.	`notifier.default`
notification_level	string	Yes	The verbosity level of notification messages to send. Valid options are 'verbose', 'info', 'error'.	`info`
approvers	list(notifier)	Yes	List of notifiers to be used for obtaining action/approval decisions.	`notifier.default`

Outputs

This pipeline has no outputs.