To remediate unrestricted Elasticsearch access in AWS using AWS CLI, follow these steps:

1. Open the AWS CLI and run the following command to list all Elasticsearch domains in your account:

   aws es list-domain-names
   

2. Identify the Elasticsearch domain that has unrestricted access.

3. Run the following command to update the Elasticsearch domain’s access policy to restrict access:

   aws es update-elasticsearch-domain-config --domain-name <domain-name> --advanced-security-options 'Enabled=true,InternalUserDatabaseEnabled=true,MasterUserOptions={MasterUserName=<master-username>,MasterUserPassword=<master-password>}'
   

   Replace <domain-name> with the name of the Elasticsearch domain and <master-username> and <master-password> with the credentials for the Elasticsearch master user.

4. Verify that access to the Elasticsearch domain is now restricted by running the following command:

   aws es describe-elasticsearch-domain-config --domain-name <domain-name>
   

   This command should return the updated access policy for the Elasticsearch domain.

5. Ensure that you have a backup of the Elasticsearch domain before making any changes to it.

To remediate unrestricted Elasticsearch access in AWS using Python, you can follow these steps:

1. Install the AWS SDK for Python (Boto3) using the following command:

pip install boto3

2. Create an AWS Identity and Access Management (IAM) client using the following code snippet:

import boto3

# Create IAM client
iam = boto3.client('iam')

3. Create an Elasticsearch service client using the following code snippet:

import boto3

# Create Elasticsearch service client
es = boto3.client('es')

4. Use the Elasticsearch service client to retrieve the Elasticsearch domain policies using the following code snippet:

import boto3

# Create Elasticsearch service client
es = boto3.client('es')

# Retrieve Elasticsearch domain policies
response = es.describe_elasticsearch_domain_config(
    DomainName='your-domain-name'
)

# Extract the Elasticsearch domain policies
policies = response['DomainConfig']['AccessPolicies']

5. Check if the Elasticsearch domain policies allow unrestricted access using the following code snippet:

import json

# Check if Elasticsearch domain policies allow unrestricted access
if '{"Effect":"Allow","Principal":"*","Action":"es:*","Resource":"arn:aws:es:*:*:domain/your-domain-name/*"}' in policies:
    # Remove the unrestricted access policy
    new_policies = json.loads(policies)
    new_policies['Statement'].remove({
        'Effect': 'Allow',
        'Principal': {'*'},
        'Action': 'es:*',
        'Resource': 'arn:aws:es:*:*:domain/your-domain-name/*'
    })
    new_policies = json.dumps(new_policies)
else:
    # No remediation needed
    new_policies = policies

6. Use the Elasticsearch service client to update the Elasticsearch domain policies using the following code snippet:

import boto3

# Create Elasticsearch service client
es = boto3.client('es')

# Update Elasticsearch domain policies
response = es.update_elasticsearch_domain_config(
    DomainName='your-domain-name',
    AccessPolicies=new_policies
)

7. Verify that the remediation was successful by checking the Elasticsearch domain policies again using the following code snippet:

import boto3

# Create Elasticsearch service client
es = boto3.client('es')

# Retrieve Elasticsearch domain policies
response = es.describe_elasticsearch_domain_config(
    DomainName='your-domain-name'
)

# Extract the Elasticsearch domain policies
policies = response['DomainConfig']['AccessPolicies']

By following these steps, you can remediate unrestricted Elasticsearch access in AWS using Python.