Cis AWS Database 2.10

2.10 Ensure Database has IAM Auth is Enabled (Manual)

Description

AuroraDB clusters should be configured to leverage AWS IAM authentication for database connections. This ensures that users authenticate using temporary IAM-based tokens rather than static long-lived passwords.

Rationale

Enabling IAM authentication for AuroraDB centralizes and strengthens access control by integrating database authentication with broader AWS IAM identity management. This approach eliminates the risks associated with hard-coded credentials, reduces administrative overhead for password rotation, and allows precise access management using IAM identities and policies.

Impact

With the usage of IAM database authentication instead of static passwords, AuroraDB clusters are protected against credential leakage and weak password practices, making unauthorized access significantly more difficult. This reduces the attack surface, supports audit and compliance, and ensures that database access is tightly aligned with enterprise identity governance and cloud security standards.

Audit Procedure

Using AWS CLI

1. List AuroraDB clusters and check IAM authentication status:

aws rds describe-db-clusters \
  --query "DBClusters[*].{DBClusterIdentifier:DBClusterIdentifier,IAMDatabaseAuthenticationEnabled:IAMDatabaseAuthenticationEnabled}" \
  --output table

2. List database users enabled for IAM authentication (Aurora MySQL):

• For MySQL, connect to the cluster and run below command to ensure that required database users exist for IAM token logins.

SELECT user, plugin FROM mysql.user WHERE plugin='AWSAuthenticationPlugin';

• For Postgres, connect to the cluster and run below command to verify that necessary users are granted the rds_iam role.

SELECT r.rolname
FROM pg_roles AS r
JOIN pg_auth_members AS m ON r.oid = m.member
JOIN pg_roles AS g ON m.roleid = g.oid
WHERE g.rolname = 'rds_iam';

The cluster must have IAM database authentication enabled and users intended for IAM authentication must exist in the database engine with appropriate privileges.

Expected Result

• IAMDatabaseAuthenticationEnabled should be true for all Aurora clusters.
• Database users configured for IAM authentication should exist (using AWSAuthenticationPlugin for MySQL or rds_iam role for PostgreSQL).

Remediation

Using AWS CLI

1. Enable IAM Database Authentication on the Aurora Cluster

Use the AWS CLI to enable IAM authentication for an existing Aurora cluster:

aws rds modify-db-cluster \
  --db-cluster-identifier <your-cluster-name> \
  --enable-iam-database-authentication \
  --apply-immediately

2. Create Local Database Users Configured for IAM Authentication

• For Aurora MySQL: Connect to the database and create or alter users as follows:

CREATE USER 'jane_doe' IDENTIFIED WITH AWSAuthenticationPlugin as 'RDS';

or

ALTER USER 'jane_doe' IDENTIFIED WITH AWSAuthenticationPlugin as 'RDS';

• For Aurora PostgreSQL:

Grant the rds_iam role to eligible users:

GRANT rds_iam TO jane_doe;

3. Grant Necessary Privileges to the Database Users

• Assign required permissions and roles to the users within your DB engine via standard SQL GRANT commands.

4. Ensure IAM Users/Roles Have Required AWS Permissions

The IAM principal that connects needs the following AWS permission in their policy:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": ["rds-db:connect"],
      "Resource": ["arn:aws:rds-db:region:account-id:dbuser:DbClusterResourceId/db-user-name"]
    }
  ]
}

• region is the AWS Region for the DB cluster
• account-id is the AWS account number for the DB cluster.
• DbClusterResourceId is the identifier for the DB cluster. This identifier is unique to an AWS Region and never changes. To find a DB cluster resource ID in the AWS Management Console for Amazon Aurora, choose the DB cluster to see its details. Then choose the Configuration tab. The Resource ID is shown in the Configuration section.

5. Test the Configuration

Use the AWS CLI to generate an authentication token:

aws rds generate-db-auth-token \
  --hostname <cluster-endpoint> \
  --port 3306 \
  --region <region> \
  --username <db_user>

Use the generated token to authenticate to the database, confirming successful login.

For mysql:

mysql --host= <cluster-endpoint> \
  --port=3306 \
  --ssl-mode=REQUIRED \
  --enable-cleartext-plugin \
  --user= <db_user_name> \
  --password= '<generated_db_auth_token>'

For postgres:

psql "host=<cluster-endpoint> port=5432 dbname=<database_name> user=<>db_user_name password='<generated_db_auth_token>' sslmode=require"

Default Value

IAM database authentication is not enabled by default on Aurora clusters.

References

• https://aws.amazon.com/products/databases/

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Level 2 | Manual