Ensure EC2 Instances are deployed in a VPC

Overview

If you created your AWS account before December 4, 2013, you might have support for EC2-Classic in some AWS Regions. Some Amazon EC2 resources and features, such as enhanced networking and newer instance types, require a virtual private cloud (VPC).

AWS and we recommend that you migrate to a VPC to take advantage of VPC-only features.

Remediation guidance

AWS remediation

Instances should run in VPC-based networking.

Console

Create/select VPC and subnets.
Launch replacement instances in VPC.
Cut over traffic and retire legacy configuration.

AWS CLI

aws ec2 run-instances \
  --image-id <ami-id> \
  --instance-type <instance-type> \
  --subnet-id <subnet-id> \
  --security-group-ids <sg-id>

References

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/vpc-migrate.html
https://docs.aws.amazon.com/cli/latest/reference/ec2/run-instances.html

Multiple Remediation Paths

AWS

SERVICE-WIDE (RECOMMENDED when many resources are affected): Deploy centralized guardrails and remediation using AWS Config Conformance Packs and (if applicable) AWS Organizations SCPs.

aws configservice put-organization-conformance-pack --organization-conformance-pack-name <pack-name> --template-s3-uri s3://<bucket>/<template>.yaml

ASSET-LEVEL: Apply the resource-specific remediation steps above to only the affected assets.

PREVENTIVE: Add CI/CD policy checks (CloudFormation/Terraform validation) before deployment to prevent recurrence.

References for Service-Wide Patterns

AWS Config Conformance Packs: https://docs.aws.amazon.com/config/latest/developerguide/conformance-packs.html
AWS Organizations SCP examples: https://docs.aws.amazon.com/organizations/latest/userguide/orgs_manage_policies_scps_examples.html

Operational Rollout Workflow

Use this sequence to reduce risk and avoid repeated drift.

1. Contain at Service-Wide Scope First (Recommended)

AWS: deploy/adjust organization conformance packs and policy guardrails.

aws configservice put-organization-conformance-pack --organization-conformance-pack-name <pack-name> --template-s3-uri s3://<bucket>/<template>.yaml

2. Remediate Existing Affected Assets

Execute the control-specific Console/CLI steps documented above for each flagged resource.
Prioritize internet-exposed and production assets first.

3. Validate and Prevent Recurrence

Re-scan after each remediation batch.
Track exceptions with owner and expiry date.
Add preventive checks in IaC/CI pipelines.

Query logic

These are the stored checks tied to this control.

EC2 Instances are deployed in a VPC

Connectors

AWS

Covered asset types

Expected check: eq []

{vms(where:{OR:[{vpcID:null},{vpcID:""}]}){...AssetFragment}}