Introduction
Amazon Web Services (AWS) Web Application Firewall (WAF) is a security solution that helps protect web applications from common threats such as SQL injection, cross-site scripting (XSS), and other vulnerabilities. The AWS Cloud Development Kit (CDK) enables developers to define cloud infrastructure using code, simplifying the provisioning and management of AWS resources. This guide provides a step-by-step approach to provisioning an AWS WAF using AWS CDK, ensuring robust application security.
Prerequisites
Before proceeding, ensure the following:
- An AWS account with necessary permissions.
- AWS CLI and AWS CDK installed.
- Node.js and TypeScript installed.
- Basic knowledge of AWS WAF and AWS CDK.
Step 1: Set Up a New AWS CDK Project
- Create a new directory for the project and navigate into it:
mkdir aws-waf-cdk && cd aws-waf-cdk
- Initialize a new CDK project:
cdk init app –language=typescript
- Install necessary dependencies:
npm install @aws-cdk/aws-wafv2
Step 2: Define AWS WAF in AWS CDK
- Open the lib/aws-waf-cdk-stack.ts file and modify it to include AWS WAF:
import * as cdk from ‘aws-cdk-lib’;
import { Construct } from ‘constructs’;
import * as wafv2 from ‘aws-cdk-lib/aws-wafv2’;
export class AwsWafCdkStack extends cdk.Stack {
constructor(scope: Construct, id: string, props?: cdk.StackProps) {
super(scope, id, props);
const webAcl = new wafv2.CfnWebACL(this, ‘WebACL’, {
scope: ‘REGIONAL’,
defaultAction: { allow: {} },
visibilityConfig: {
sampledRequestsEnabled: true,
cloudWatchMetricsEnabled: true,
metricName: ‘WebACLMetric’,
},
rules: [
{
name: ‘BlockSQLInjection’,
priority: 1,
statement: {
sqliMatchStatement: {
fieldToMatch: { uriPath: {} },
textTransformations: [{ priority: 0, type: ‘URL_DECODE’ }],
},
},
action: { block: {} },
visibilityConfig: {
sampledRequestsEnabled: true,
cloudWatchMetricsEnabled: true,
metricName: ‘BlockSQLInjectionMetric’,
},
},
],
});
}
}
Step 3: Deploy the AWS WAF Stack
- Synthesize the AWS CDK stack:
cdk synth
Deploy the AWS WAF stack to AWS:
cdk deploy
Step 4: Verify Deployment
Once deployment is complete:
- Navigate to the AWS WAF console.
- Confirm that the WebACL appears under the configured region.
- Check the associated rules to ensure correct configurations.
Conclusion
Provisioning AWS WAF using AWS CDK automates the setup process, ensuring a scalable and secure application infrastructure. By leveraging infrastructure-as-code (IaC), developers can maintain security policies as part of the deployment workflow, reducing manual configurations and enhancing application protection against web threats.