Amazon OpenSearch Service controls

These controls are related to OpenSearch Service resources.

[Opensearch.1] OpenSearch domains should have encryption at rest enabled

Related requirements: PCI DSS v3.2.1/1.2.1, PCI DSS v3.2.1/1.3.1, PCI DSS v3.2.1/1.3.4, PCI DSS v3.2.1/7.2.1, NIST.800-53.r5 CA-9(1), NIST.800-53.r5 CM-3(6), NIST.800-53.r5 SC-13, NIST.800-53.r5 SC-28, NIST.800-53.r5 SC-28(1), NIST.800-53.r5 SI-7(6)

Category: Protect > Data protection > Encryption of data at rest

Severity: Medium

Resource type: AWS::OpenSearch::Domain

AWS Config rule: opensearch-encrypted-at-rest

Schedule type: Change triggered

Parameters: None

This control checks whether OpenSearch domains have encryption-at-rest configuration enabled. The check fails if encryption at rest is not enabled.

For an added layer of security for sensitive data, you should configure your OpenSearch Service domain to be encrypted at rest. When you configure encryption of data at rest, AWS KMS stores and manages your encryption keys. To perform the encryption, AWS KMS uses the Advanced Encryption Standard algorithm with 256-bit keys (AES-256).

To learn more about OpenSearch Service encryption at rest, see Encryption of data at rest for Amazon OpenSearch Service in the Amazon OpenSearch Service Developer Guide.

Note

This control is not supported in Middle East (UAE).

Remediation

By default, domains do not encrypt data at rest, and you cannot configure existing domains to use the feature. To enable the feature, you must create another domain and migrate your data.

For information about creating domains, see Creating and managing Amazon OpenSearch Service domains in the Amazon OpenSearch Service Developer Guide.

Encryption of data at rest requires Amazon OpenSearch 1.0 or later. For more information about encrypting data at rest for Amazon OpenSearch, see Encryption of data at rest for Amazon OpenSearch Service in the Amazon OpenSearch Service Developer Guide.

[Opensearch.2] OpenSearch domains should be in a VPC

Related requirements: PCI DSS v3.2.1/1.2.1, PCI DSS v3.2.1/1.3.1, PCI DSS v3.2.1/1.3.2, PCI DSS v3.2.1/1.3.4, PCI DSS v3.2.1/1.3.6, NIST.800-53.r5 AC-21, NIST.800-53.r5 AC-3, NIST.800-53.r5 AC-3(7), NIST.800-53.r5 AC-4, NIST.800-53.r5 AC-4(21), NIST.800-53.r5 AC-6, NIST.800-53.r5 SC-7, NIST.800-53.r5 SC-7(11), NIST.800-53.r5 SC-7(16), NIST.800-53.r5 SC-7(20), NIST.800-53.r5 SC-7(21), NIST.800-53.r5 SC-7(3), NIST.800-53.r5 SC-7(4), NIST.800-53.r5 SC-7(9)

Category: Protect > Secure network configuration > Resources within VPC

Severity: Critical

Resource type: AWS::OpenSearch::Domain

AWS Config rule: opensearch-in-vpc-only

Schedule type: Change triggered

Parameters: None

This control checks whether OpenSearch domains are in a VPC. It does not evaluate the VPC subnet routing configuration to determine public access.

You should ensure that OpenSearch domains are not attached to public subnets. See Resource-based policies in the Amazon OpenSearch Service Developer Guide. You should also ensure that your VPC is configured according to the recommended best practices. See Security best practices for your VPC in the Amazon VPC User Guide.

OpenSearch domains deployed within a VPC can communicate with VPC resources over the private AWS network, without the need to traverse the public internet. This configuration increases the security posture by limiting access to the data in transit. VPCs provide a number of network controls to secure access to OpenSearch domains, including network ACL and security groups. Security Hub recommends that you migrate public OpenSearch domains to VPCs to take advantage of these controls.

Note

This control is not supported in Middle East (UAE).

Remediation

If you create a domain with a public endpoint, you cannot later place it within a VPC. Instead, you must create a new domain and migrate your data. The reverse is also true. If you create a domain within a VPC, it cannot have a public endpoint.

Instead, you must either create another domain or disable this control.

See Launching your Amazon OpenSearch Service domains within a VPC in the Amazon OpenSearch Service Developer Guide.

[Opensearch.3] OpenSearch domains should encrypt data sent between nodes

Related requirements: NIST.800-53.r5 AC-4, NIST.800-53.r5 SC-13, NIST.800-53.r5 SC-23, NIST.800-53.r5 SC-23(3), NIST.800-53.r5 SC-7(4), NIST.800-53.r5 SC-8, NIST.800-53.r5 SC-8(1), NIST.800-53.r5 SC-8(2)

Category: Protect > Data protection > Encryption of data in transit

Severity: Medium

Resource type: AWS::OpenSearch::Domain

AWS Config rule: opensearch-node-to-node-encryption-check

Schedule type: Change triggered

Parameters: None

This control checks whether OpenSearch domains have node-to-node encryption enabled. This control fails if node-to-node encryption is disabled on the domain.

HTTPS (TLS) can be used to help prevent potential attackers from eavesdropping on or manipulating network traffic using person-in-the-middle or similar attacks. Only encrypted connections over HTTPS (TLS) should be allowed. Enabling node-to-node encryption for OpenSearch domains ensures that intra-cluster communications are encrypted in transit.

There can be a performance penalty associated with this configuration. You should be aware of and test the performance trade-off before enabling this option.

Note

This control is not supported in Middle East (UAE).

Remediation

Node-to-node encryption can only be enabled on a new domain. To remediate this finding, create a new domain with Node-to-node encryption enabled and migrate your data to the new domain. Follow the instructions to create a new domain in the Amazon OpenSearch Service Developer Guide and ensure that you select the Node-to-node encryption option when creating the new domain. Then follow Using a snapshot to migrate data to migrate your data to the new domain.

[Opensearch.4] OpenSearch domain error logging to CloudWatch Logs should be enabled

Related requirements: NIST.800-53.r5 AC-2(4), NIST.800-53.r5 AC-4(26), NIST.800-53.r5 AC-6(9), NIST.800-53.r5 AU-10, NIST.800-53.r5 AU-12, NIST.800-53.r5 AU-2, NIST.800-53.r5 AU-3, NIST.800-53.r5 AU-6(3), NIST.800-53.r5 AU-6(4), NIST.800-53.r5 CA-7, NIST.800-53.r5 SC-7(9), NIST.800-53.r5 SI-3(8), NIST.800-53.r5 SI-4(20), NIST.800-53.r5 SI-7(8)

Category: Identify > Logging

Severity: Medium

Resource type: AWS::OpenSearch::Domain

AWS Config rule: opensearch-logs-to-cloudwatch

Schedule type: Change triggered

Parameters:

• logtype = 'error'

This control checks whether OpenSearch domains are configured to send error logs to CloudWatch Logs. This control fails if error logging to CloudWatch is not enabled for a domain.

You should enable error logs for OpenSearch domains and send those logs to CloudWatch Logs for retention and response. Domain error logs can assist with security and access audits, and can help to diagnose availability issues.

Note

This control is not supported in Middle East (UAE).

Remediation

For information on how to enable log publishing, see Enabling log publishing (console) in the Amazon OpenSearch Service Developer Guide.

[Opensearch.5] OpenSearch domains should have audit logging enabled

Related requirements: NIST.800-53.r5 AC-2(4), NIST.800-53.r5 AC-4(26), NIST.800-53.r5 AC-6(9), NIST.800-53.r5 AU-10, NIST.800-53.r5 AU-12, NIST.800-53.r5 AU-2, NIST.800-53.r5 AU-3, NIST.800-53.r5 AU-6(3), NIST.800-53.r5 AU-6(4), NIST.800-53.r5 CA-7, NIST.800-53.r5 SC-7(9), NIST.800-53.r5 SI-3(8), NIST.800-53.r5 SI-4(20), NIST.800-53.r5 SI-7(8)

Category: Identify > Logging

Severity: Medium

Resource type: AWS::OpenSearch::Domain

AWS Config rule: opensearch-audit-logging-enabled

Schedule type: Change triggered

Parameters:

• cloudWatchLogsLogGroupArnList (Optional). Security Hub does not populate this parameter. Comma-separated list of CloudWatch Logs log groups that should be configured for audit logs.

This rule is NON_COMPLIANT if the CloudWatch Logs log group of the OpenSearch domain is not specified in this parameter list.

This control checks whether OpenSearch domains have audit logging enabled. This control fails if an OpenSearch domain does not have audit logging enabled.

Audit logs are highly customizable. They allow you to track user activity on your OpenSearch clusters, including authentication successes and failures, requests to OpenSearch, index changes, and incoming search queries.

Note

This control is not supported in Middle East (UAE).

Remediation

For detailed instructions on enabling audit logs, see Enabling audit logs in the Amazon OpenSearch Service Developer Guide.

[Opensearch.6] OpenSearch domains should have at least three data nodes

Related requirements: NIST.800-53.r5 CP-10, NIST.800-53.r5 CP-6(2), NIST.800-53.r5 SC-36, NIST.800-53.r5 SC-5(2), NIST.800-53.r5 SI-13(5)

Category: Recover > Resilience > High availability

Severity: Medium

Resource type: AWS::OpenSearch::Domain

AWS Config rule: opensearch-data-node-fault-tolerance

Schedule type: Change triggered

Parameters: None

This control checks whether OpenSearch domains are configured with at least three data nodes and zoneAwarenessEnabled is true. This control fails for an OpenSearch domain if instanceCount is less than 3 or zoneAwarenessEnabled is false.

An OpenSearch domain requires at least three data nodes for high availability and fault-tolerance. Deploying an OpenSearch domain with at least three data nodes ensures cluster operations if a node fails.

Note

This control is not supported in Middle East (UAE).

Remediation

To modify the number of data nodes in an OpenSearch domain

1. Sign in to the AWS console and open the Amazon OpenSearch Service console at https://console.aws.amazon.com/es/.

2. Under My domains, choose the name of the domain to edit, and choose Edit.

3. Under Data nodes set Number of nodes to a number greater than 3. If you are deploying to three Availability Zone, set the number to a multiple of three to ensure equal distribution across Availability Zones.

4. Choose Submit.

[Opensearch.7] OpenSearch domains should have fine-grained access control enabled

Related requirements: NIST.800-53.r5 AC-2(1), NIST.800-53.r5 AC-3, NIST.800-53.r5 AC-3(15), NIST.800-53.r5 AC-3(7), NIST.800-53.r5 AC-5, NIST.800-53.r5 AC-6

Category: Protect > Secure Access Management > Sensitive API actions restricted

Severity: High

Resource type: AWS::OpenSearch::Domain

AWS Config rule: opensearch-access-control-enabled

Schedule type: Change triggered

Parameters: None

This control checks whether OpenSearch domains have fine-grained access control enabled. The control fails if the fine-grained access control is not enabled. Fine-grained access control requires advanced-security-optionsin the OpenSearch parameter update-domain-config to be enabled.

Fine-grained access control offers additional ways of controlling access to your data on Amazon OpenSearch Service.

Note

This control is not supported in the following Regions:

• Africa (Cape Town)

• Asia Pacific (Jakarta)

• Asia Pacific (Osaka)

• China (Beijing)

• China (Ningxia)

• Europe (Milan)

• Middle East (UAE)

• AWS GovCloud (US-East)

• AWS GovCloud (US-West)

Remediation

To enable fine-grained access control, see Fine-grained access control in Amazon OpenSearch Service in the Amazon OpenSearch Service Developer Guide.

[Opensearch.8] Connections to OpenSearch domains should be encrypted using TLS 1.2

Related requirements: NIST.800-53.r5 AC-17(2), NIST.800-53.r5 AC-4, NIST.800-53.r5 IA-5(1), NIST.800-53.r5 SC-12(3), NIST.800-53.r5 SC-13, NIST.800-53.r5 SC-23, NIST.800-53.r5 SC-23(3), NIST.800-53.r5 SC-7(4), NIST.800-53.r5 SC-8, NIST.800-53.r5 SC-8(1), NIST.800-53.r5 SC-8(2), NIST.800-53.r5 SI-7(6)

Category: Protect > Data protection > Encryption of data-in-transit

Severity: Medium

Resource type: AWS::OpenSearch::Domain

AWS Config rule: opensearch-https-required

Schedule type: Change triggered

Parameters: None

This control checks whether connections to OpenSearch domains are required to use TLS 1.2. The check fails if the OpenSearch domain TLSSecurityPolicy is not Policy-Min-TLS-1-2-2019-07.

HTTPS (TLS) can be used to help prevent potential attackers from using person-in-the-middle or similar attacks to eavesdrop on or manipulate network traffic. Only encrypted connections over HTTPS (TLS) should be allowed. Encrypting data in transit can affect performance. You should test your application with this feature to understand the performance profile and the impact of TLS. TLS 1.2 provides several security enhancements over previous versions of TLS.

Note

This control is not supported in Middle East (UAE).

Remediation

To enable TLS encryption, use the UpdateDomainConfig API operation to configure the DomainEndpointOptions in order to set the TLSSecurityPolicy. For more information, see Node-to-node encryption in the Amazon OpenSearch Service Developer Guide.