To avoid exposing sensitive data and mitigate security risks, it is crucial to ensure that your Amazon Database Migration Service (DMS) instances are not accessible to the public via the internet. This can be achieved by configuring the DMS replication instance to have a private IP address and disabling the Publicly Accessible feature, especially when the source and target databases are in the same network connected to the instance's VPC via a VPN, VPC peering connection, or AWS Direct Connect dedicated connection. If DMS replication instances have public IP addresses and are publicly accessible, any machine outside the VPC can connect to them, increasing the attack surface and the risk of malicious activity. Although the level of access to DMS instances may vary based on their use cases, in most scenarios, the instances should only be privately accessible within the Amazon Virtual Private Cloud (VPC).


To ensure that your Amazon Database Migration Service (DMS) instances are not publicly accessible, you can follow these remediation steps:

  1. Disable Public Accessibility: When creating or modifying your DMS replication instance, ensure that the "Publicly Accessible" option is disabled. This will ensure that the instance is not publicly accessible via the internet.
  2. Use Private Subnets: Ensure that your DMS instances are placed in private subnets that do not have a route to the internet. This will prevent internet traffic from reaching your instances.
  3. Use Security Groups: Create and apply a security group to your DMS instance that restricts access to only specific IP addresses or CIDR ranges. This will limit access to your DMS instance to only those IP addresses that you have explicitly allowed.
  4. Use VPC Endpoints: Use VPC endpoints to connect to your DMS instance without the need for internet access. VPC endpoints provide a secure and private connection between your VPC and DMS instance.
  5. Use IAM Policies: Use IAM policies to control access to your DMS instances. For example, you can create an IAM policy that allows only specific users or roles to access your DMS instances.

By implementing these remediation steps, you can ensure that your DMS instances are not publicly accessible, and only authorized users with the appropriate permissions can access them. This will help to minimize the risk of unauthorized access and potential data breaches.

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Note: Remediation steps provided by Lightlytics are meant to be suggestions and guidelines only. It is crucial to thoroughly verify and test any remediation steps before applying them to production environments. Each organization's infrastructure and security needs may differ, and blindly applying suggested remediation steps without proper testing could potentially cause unforeseen issues or vulnerabilities. Therefore, it is strongly recommended that you validate and customize any remediation steps to meet your organization's specific requirements and ensure that they align with your security policies and best practices.