​
Event Information

  • The CreateRule event in AWS WAF refers to the action of creating a new rule within a Web Application Firewall (WAF) configuration.
  • This event is triggered when a user or an automated process creates a rule to define specific conditions and actions for filtering and blocking incoming web traffic.
  • The CreateRule event allows administrators to customize their WAF configuration by adding rules that match specific patterns or criteria, such as blocking requests containing malicious code or known attack patterns.

​
Examples

  1. Misconfiguration of CreateRule: If the CreateRule operation is not properly configured, it can lead to security vulnerabilities. For example, if the rule allows unrestricted access or does not effectively filter out malicious traffic, it can compromise the security of the web application firewall (WAF).
  2. Inadequate rule logic: If the rule logic defined in CreateRule is not comprehensive or accurate, it can result in false positives or false negatives. False positives can block legitimate traffic, causing inconvenience to users, while false negatives can allow malicious traffic to bypass the WAF, leading to potential security breaches.
  3. Lack of regular rule updates: If the CreateRule operation is not regularly updated with the latest threat intelligence and security best practices, it can become ineffective in protecting against emerging threats. Outdated rules may not be able to detect and mitigate new attack vectors, leaving the system vulnerable to security risks. Regular updates and maintenance of rules are crucial to ensure the ongoing security of the WAF.

​
Remediation

​
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.
    • Navigate to the AWS WAF service.
    • Select the appropriate WebACL that contains the rule that needs to be remediated.
  2. Modify the AWS WAF rule to address the identified issue.
    • Within the selected WebACL, locate the rule that needs to be remediated.
    • Click on the rule to access its configuration settings.
    • Adjust the rule’s conditions, filters, or actions as necessary to address the issue.
    • Save the changes made to the rule.
  3. Test and monitor the remediated AWS WAF rule.
    • Deploy the updated WebACL to the appropriate AWS resources (e.g., CloudFront distribution, Application Load Balancer).
    • Monitor the traffic and logs to ensure that the remediated rule is functioning as expected.
    • Continuously monitor and analyze the logs and metrics to identify any potential issues or anomalies.
    • Make further adjustments to the rule if necessary based on the observed behavior.

​
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 in the WebACL, setting the action to ALLOW and overriding any previous actions.
  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 in the WebACL, setting 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-owasp-top-10 to the latest available version, you can use the following command: 
    aws wafv2 update-managed-rule-set-version --name gbqj2j5k5k-owasp-top-10 --scope REGIONAL --vendor-name aws-managed
    This command updates the specified managed rule group to the latest available version, ensuring that you have the latest security protections in place.

​
Using Python

  1. Example 1: Blocking IP addresses with AWS WAF using Python
To remediate this issue, you can use the AWS SDK for Python (Boto3) to automate the process of blocking IP addresses in AWS WAF. Here’s a Python script that demonstrates how to achieve this: 
import boto3

def block_ip_address(ip_address):
    waf_client = boto3.client('waf')

    # Get the IP set identifier
    response = waf_client.get_ip_set(
        IPSetId='your_ip_set_id'
    )
    ip_set = response['IPSet']

    # Add the IP address to the IP set
    ip_set['IPSetDescriptors'].append({
        'Type': 'IPV4',
        'Value': ip_address
    })

    # Update the IP set
    waf_client.update_ip_set(
        IPSetId='your_ip_set_id',
        ChangeToken='your_change_token',
        Updates=[
            {
                'Action': 'INSERT',
                'IPSetDescriptor': {
                    'Type': 'IPV4',
                    'Value': ip_address
                }
            }
        ]
    )

    print(f"Successfully blocked IP address: {ip_address}")

# Usage example
block_ip_address('192.168.0.1')
  1. Example 2: Creating a rate-based rule with AWS WAF using Python
To remediate this issue, you can use the AWS SDK for Python (Boto3) to automate the process of creating a rate-based rule in AWS WAF. Here’s a Python script that demonstrates how to achieve this: 
import boto3

def create_rate_based_rule(rule_name, metric_name, rate_limit):
    waf_client = boto3.client('waf')

    # Create the rate-based rule
    response = waf_client.create_rate_based_rule(
        Name=rule_name,
        MetricName=metric_name,
        RateLimit=rate_limit,
        ChangeToken='your_change_token'
    )

    print(f"Successfully created rate-based rule: {response['Rule']['RuleId']}")

# Usage example
create_rate_based_rule('MyRateBasedRule', 'MyMetric', 1000)
  1. Example 3: Updating a web ACL with AWS WAF using Python
To remediate this issue, you can use the AWS SDK for Python (Boto3) to automate the process of updating a web ACL in AWS WAF. Here’s a Python script that demonstrates how to achieve this: 
import boto3

def update_web_acl(web_acl_id, rule_id):
    waf_client = boto3.client('waf')

    # Get the current web ACL configuration
    response = waf_client.get_web_acl(
        WebACLId=web_acl_id
    )
    web_acl = response['WebACL']

    # Add the rule to the web ACL
    web_acl['Rules'].append({
        'Action': 'BLOCK',
        'Priority': 1,
        'RuleId': rule_id
    })

    # Update the web ACL
    waf_client.update_web_acl(
        WebACLId=web_acl_id,
        ChangeToken='your_change_token',
        Updates=[
            {
                'Action': 'INSERT',
                'ActivatedRule': {
                    'Priority': 1,
                    'RuleId': rule_id,
                    'Action': {
                        'Type': 'BLOCK'
                    }
                }
            }
        ]
    )

    print(f"Successfully updated web ACL: {web_acl_id}")

# Usage example
update_web_acl('your_web_acl_id', 'your_rule_id')