Elastic MapReduce (EMR) is a managed cluster platform that simplifies the process of running big data frameworks. EMR cluster is a collection EC2 instances, while each instance in the cluster is called a node. The master node manages the cluster and coordinates the distribution of data and tasks among other nodes for processing. As a security practice best practice, you should ensure that the security groups associated with your EMR master nodes are not open to the internet, which limits access to the clusters to your private network or approved IP addresses or security groups. By doing so, you can protect your EMR clusters from unauthorized access, as external parties will not be able to connect to them over the internet.
To ensure that EMR cluster master nodes are not publicly accessible, you can take the following remediation steps:
- Move the master node to a private subnet or VPC - This will ensure that the master node is not directly exposed to the internet and can only be accessed through a private network.
- Remove the public IP address associated with the master node - If the master node is currently associated with a public IP address, remove it to prevent direct access from the internet.
- Enable SSH tunneling - Enable SSH tunneling to create a secure access to the master node.
- Restrict access to the cluster - Restrict access to the EMR cluster by configuring security groups and network ACLs to limit access to only the necessary IP addresses and ports.
- Use VPN or Direct Connect - Use a VPN or Direct Connect to access the EMR cluster securely from outside of the AWS network.
By following these remediation steps, you can ensure that your EMR cluster master nodes are not publicly accessible and are properly secured.
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.