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Event Information

  • The DeleteRateBasedRule event in AWS WAF refers to the action of deleting a rate-based rule from a web application firewall (WAF) configuration.
  • Rate-based rules in AWS WAF are used to protect against HTTP flood attacks by setting a threshold for the number of requests from a specific IP address within a specified time period.
  • When the DeleteRateBasedRule event occurs, it means that a rate-based rule has been removed from the WAF configuration, potentially impacting the protection against HTTP flood attacks for the associated web application.

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Examples

  1. Unauthorized deletion: If security is impacted with DeleteRateBasedRule in AWS WAF, one example could be an unauthorized user gaining access to the AWS Management Console or API credentials and deleting a rate-based rule. This could result in the removal of a critical security control, allowing malicious traffic to bypass WAF protections.
  2. Misconfiguration: Another example could be a misconfiguration in the AWS WAF settings, where a rate-based rule is unintentionally deleted or disabled. This could leave the application vulnerable to DDoS attacks or other malicious activities, compromising the security of the system.
  3. Insider threat: A potential security impact could arise from an insider threat scenario, where a trusted employee or administrator with elevated privileges intentionally deletes a rate-based rule. This could be done with malicious intent, such as enabling a competitor’s traffic to overwhelm the application or to bypass security controls for personal gain.

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Remediation

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Using Console

  1. Identify the specific AWS WAF rule that needs to be remediated based on the examples provided.
    • Log in to the AWS Management Console and navigate to the AWS WAF service.
    • Select the appropriate web ACL that contains the rule that needs to be remediated.
  2. Modify the AWS WAF rule to address the identified issue.
    • Within the selected web ACL, locate the rule that needs to be remediated.
    • Click on the rule to access its configuration settings.
    • Adjust the rule’s parameters or conditions to align with the desired remediation action.
    • Save the changes made to the rule.
  3. Test and monitor the remediated AWS WAF rule.
    • Deploy the updated web ACL to the appropriate AWS resources (e.g., Amazon CloudFront distribution, Application Load Balancer).
    • Monitor the traffic and behavior of the protected resources to ensure that the remediated rule is functioning as expected.
    • Continuously monitor and analyze the AWS WAF logs and metrics to identify any potential issues or anomalies that may require further remediation.
Note: The specific steps may vary depending on the AWS WAF console interface and the nature of the rule being remediated. It is important to refer to the AWS documentation for detailed instructions and best practices.

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Using CLI

  1. To remediate a specific rule in AWS WAF using AWS CLI, you can use the update-rule command. For example, if you want to update a rule with the ID 12345678-1234-1234-1234-123456789012 in a WebACL named MyWebACL, you can use the following command: 
    aws wafv2 update-rule --name MyWebACL --scope REGIONAL --id 12345678-1234-1234-1234-123456789012 --action ALLOW --override-action NONE
    This command updates the specified rule to allow the traffic and sets the override action to none.
  2. To remediate a rate-based rule in AWS WAF using AWS CLI, you can use the update-rate-based-rule command. For example, if you want to update a rate-based rule with the ID 12345678-1234-1234-1234-123456789012 in a WebACL named MyWebACL, you can use the following command: 
    aws wafv2 update-rate-based-rule --name MyWebACL --scope REGIONAL --id 12345678-1234-1234-1234-123456789012 --rate-limit 1000
    This command updates the specified rate-based rule to set the rate limit to 1000 requests per 5 minutes.
  3. To remediate a managed rule group in AWS WAF using AWS CLI, you can use the update-managed-rule-set-version command. For example, if you want to update a managed rule group with the ARN arn:aws:wafv2:us-west-2:123456789012:managed-rule-set/aws-managed/gbqj2j5k5k in a WebACL named MyWebACL, you can use the following command: 
    aws wafv2 update-managed-rule-set-version --name MyWebACL --scope REGIONAL --id arn:aws:wafv2:us-west-2:123456789012:managed-rule-set/aws-managed/gbqj2j5k5k --version 3
    This command updates the specified managed rule group to use version 3 of the rule set.

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Using Python

To remediate AWS WAF issues using Python, you can utilize the AWS SDK (Boto3) to interact with the AWS WAF API. Here are three examples of how you can remediate AWS WAF issues using Python:
  1. Example 1: Updating a WebACL Rule:
import boto3

def update_webacl_rule(webacl_id, rule_id, new_action):
    waf_client = boto3.client('waf')

    response = waf_client.update_rule(
        RuleId=rule_id,
        ChangeToken=waf_client.get_change_token()['ChangeToken'],
        Updates=[
            {
                'Action': 'INSERT',
                'ActivatedRule': {
                    'Priority': 1,
                    'RuleId': rule_id,
                    'Action': {
                        'Type': new_action
                    }
                }
            }
        ]
    )

    response = waf_client.update_web_acl(
        WebACLId=webacl_id,
        ChangeToken=waf_client.get_change_token()['ChangeToken'],
        Updates=[
            {
                'Action': 'INSERT',
                'ActivatedRule': {
                    'Priority': 1,
                    'RuleId': rule_id,
                    'Action': {
                        'Type': new_action
                    }
                }
            }
        ]
    )

    print("WebACL rule updated successfully.")

# Usage
update_webacl_rule('webacl-123456', 'rule-123456', 'BLOCK')
  1. Example 2: Creating a new WebACL:
import boto3

def create_webacl(webacl_name, rule_ids):
    waf_client = boto3.client('waf')

    response = waf_client.create_web_acl(
        Name=webacl_name,
        MetricName=webacl_name,
        DefaultAction={
            'Type': 'ALLOW'
        },
        ChangeToken=waf_client.get_change_token()['ChangeToken']
    )

    webacl_id = response['WebACL']['WebACLId']

    for i, rule_id in enumerate(rule_ids):
        response = waf_client.update_web_acl(
            WebACLId=webacl_id,
            ChangeToken=waf_client.get_change_token()['ChangeToken'],
            Updates=[
                {
                    'Action': 'INSERT',
                    'ActivatedRule': {
                        'Priority': i + 1,
                        'RuleId': rule_id,
                        'Action': {
                            'Type': 'BLOCK'
                        }
                    }
                }
            ]
        )

    print("WebACL created successfully.")

# Usage
create_webacl('new-webacl', ['rule-123456', 'rule-789012'])
  1. Example 3: Deleting a WebACL:
import boto3

def delete_webacl(webacl_id):
    waf_client = boto3.client('waf')

    response = waf_client.delete_web_acl(
        WebACLId=webacl_id,
        ChangeToken=waf_client.get_change_token()['ChangeToken']
    )

    print("WebACL deleted successfully.")

# Usage
delete_webacl('webacl-123456')
Please note that these examples are just for reference and you may need to modify them based on your specific requirements and the structure of your AWS WAF configuration.