Automated DAST Testing in CI/CD Environments with OWASP ZAP

OWASP ZAP Vulnerability Penetration test Proxy server

Dynamic Application Security Testing (DAST) is a vital practice for identifying vulnerabilities in web applications by simulating real-world attacks. Automating DAST within your CI/CD pipeline ensures that security testing is performed consistently and efficiently throughout the software development lifecycle. This article will guide you through implementing automated DAST in your CI/CD environment, with a focus on leveraging the powerful and popular open-source tool, OWASP ZAP.

1. Choosing Your DAST Tool: The Power of OWASP ZAP

OWASP ZAP (Zed Attack Proxy) is a free, open-source tool that stands out as a particularly strong choice for integrating into CI/CD pipelines.

Why OWASP ZAP?

Open Source and Free: Being open-source, ZAP is freely available and benefits from a large and active community, ensuring continuous development and support.

  • Feature-Rich: ZAP offers a wide range of features, including automated scanning, spidering, a proxy server, and scripting capabilities.
  • CI/CD Friendly: ZAP provides robust command-line options, making it ideal for integration into automated workflows. It can also be run within a Docker container, simplifying deployment and management within your CI/CD environment.
  • Automation Capabilities: ZAP includes a powerful API and supports various scripting languages (such as Python or JavaScript) enabling you to customize and automate your scans.
  • Extensive Documentation and Community Support: ZAP boasts comprehensive documentation and a helpful community, making it easier to get started and resolve any issues. While other tools like Codename SCNR or enterprise-grade options like Invicti, Acunetix, and Burp Suite Professional are worth considering, ZAP's combination of features, ease of use, and open-source nature makes it a great fit for many teams implementing automated DAST.

2. Integrating OWASP ZAP into Your CI/CD Pipeline

Integrating ZAP into your CI/CD pipeline involves a few key steps:

  • Select a CI/CD Platform: Popular choices include Jenkins, GitLab CI/CD, GitHub Actions, Azure DevOps, and CircleCI. Select the platform that aligns best with your team's existing infrastructure and workflow.
  • Installing and Configuring OWASP ZAP: The recommended approach for CI/CD integration is to use the official OWASP ZAP Docker image. This ensures consistency across environments and simplifies management. You can pull the stable or weekly image from Docker Hub and use it directly in your pipeline.
  • Define a DAST Stage: Create a dedicated stage within your CI/CD pipeline specifically for running ZAP. This stage should be positioned after your application has been built and deployed to a test environment. This guarantees that ZAP is testing a live, functioning instance of your application.

3. Configuring Your ZAP Scan

Properly configuring your ZAP scan is crucial to its effectiveness. ZAP offers various command-line options and API functionalities to customize your scans:

  • Target URL: Use the -t option to specify the target URL of your application in the test environment.
  • Authentication: ZAP provides multiple ways to handle authentication:
    • Zest Scripts: You can record authentication sequences using ZAP's Zest scripting capabilities and replay them during the scan.
    • Context Files: Define contexts within ZAP that include authentication details.
    • Command-line options: Pass usernames and passwords directly (though less secure).
  • Scan Scope: Control which parts of your application are scanned.
    • -r option: Generate a traditional spider report of the links found.
    • -d option: Show the details of the scan.
    • Contexts: Define contexts to include or exclude specific URLs or directories, refining the scan's focus.
  • Scan Policy: ZAP uses scan policies to define the types of attacks and vulnerabilities it checks for.
    • -x option: Generates an XML report of the scan, including the scan policy details.
    • Pre-built policies: The baseline scan policy is great for initial testing.
    • Custom policies: You can create custom policies tailored to your application's risk profile.
  • Scheduling: Integrate ZAP into your CI/CD pipeline to run automatically. Trigger scans on every push to the main branch, on a nightly schedule, or based on your specific release cycle.

4. Analyzing and Reporting on ZAP Results

After the ZAP scan completes, you need to analyze the results and take action:

  • Parse Results: ZAP can generate reports in various formats, including XML, JSON, and HTML. Configure your pipeline to parse the chosen format and extract key data like vulnerability type, severity (High, Medium, Low), URL, and description. ZAP provides options to specify the report format using flags like -x (XML), -j (JSON), or -w (HTML).
  • Fail the Build (Implement a Security Gate): Establish a clear security threshold. Configure your CI/CD pipeline to automatically fail the build if ZAP detects vulnerabilities exceeding a predefined severity level (e.g., any "High" severity issues). This creates a critical security checkpoint, preventing vulnerable code from moving forward.
  • Generate Reports: Use ZAP's built-in reporting features or CI/CD plugins to generate comprehensive reports. These reports should be easy for developers and security teams to understand, providing actionable insights for remediation. Integrate with issue trackers, and communication tools like Slack or email, to keep everyone informed.

Examples

  1. AWS CodePipeline and CodeBuild with OWASP ZAP:

This is the AWS CodeBuild buildspec.yml file:

version: 0.2

phases:
  pre_build:
    commands:
      - echo Logging in to Amazon ECR...
      - aws ecr get-login-password --region $AWS_REGION | docker login --username AWS --password-stdin $AWS_ACCOUNT_ID.dkr.ecr.$AWS_REGION.amazonaws.com
  build:
    commands:
      - echo Build started on `date`
      - echo Starting OWASP ZAP scan...
      - docker pull owasp/zap2docker-stable
      - docker run -t owasp/zap2docker-stable zap-baseline.py -t $TARGET_URL -r ZAP-Report.html
  post_build:
    commands:
      - echo ZAP scan completed on `date`
      - aws s3 cp ZAP-Report.html s3://$S3_BUCKET_NAME/
      - echo Checking for critical vulnerabilities...
      - |
        if docker run -t owasp/zap2docker-stable zap-cli status -m 1 -a; then
          echo "No High or Medium severity vulnerabilities found."
        else
          echo "High or Medium severity vulnerabilities found! Failing build."
          exit 1
        fi
artifacts:
  files:
    - ZAP-Report.html

Notes:

  • pre_build: Logs into Amazon ECR if you need to pull private images for your application.
  • build:
    • Pulls the owasp/zap2docker-stable Docker image.
    • Runs the zap-baseline.py script, which is included in the ZAP Docker image.
    • -t $TARGET_URL: Specifies the target URL of your application. You would set TARGET_URL as an environment variable in your CodeBuild project.
    • -r ZAP-Report.html: Generates an HTML report named ZAP-Report.html
  • post_build:
    • Uploads the report to an S3 bucket. You'll need to create an S3 bucket and replace $S3_BUCKET_NAME with your bucket name.
    • Uses zap-cli status to check for alerts. -m 1 checks for alerts of Medium severity or above and -a causes zap-cli to fail if alerts are found. This will fail the build if high or medium-severity issues are detected.
  • artifacts: Specifies that the ZAP-Report.html should be saved as a build artifact.

CodePipeline Configuration:

  • Source Stage: Pulls the latest code from your repository.
  • Build Stage:
    • Select AWS CodeBuild as the build provider.
    • Create a new CodeBuild project or use an existing one.
    • Configure the project to use the buildspec.yml file above.
    • Set the TARGET_URL environment variable to the URL of your application in the test environment.
    • Configure the build project to have access to your S3 bucket (use an IAM role).
  • Deploy Stage: Deploy to your test environment or whatever.
  1. GitLab CI/CD with OWASP ZAP:

This goes in your .gitlab-ci.yml file:

stages:
  - build
  - test
  - dast

variables:
  TARGET_URL: "https://your-test-environment.com"

build_job:
  stage: build
  script:
    - echo "Building application..."
    # Add your build commands

test_job:
  stage: test
  script:
    - echo "Running tests..."
    # Add any other test commands

dast:
  stage: dast
  image: owasp/zap2docker-stable
  script:
    - zap-baseline.py -t $TARGET_URL -r ZAP-Report.html
    - |
      if zap-cli status -m 1 -a; then
        echo "No High or Medium vulnerabilities found."
      else
        echo "High or Medium vulnerabilities found! Failing build."
        exit 1
      fi
  artifacts:
    paths:
      - ZAP-Report.html
    reports:
      dast: ZAP-Report.html
  • stages: Defines the order of stages in the pipeline.
  • variables: Defines the TARGET_URL variable, replace with the URL of your application in its test environment.
  • build_job and test_job: These are here for illustration - you would use these to include your application's build and test steps.
  • dast:
    • Uses the owasp/zap2docker-stable image.
    • Runs zap-baseline.py with the target URL and generates an HTML report.
    • Uses zap-cli status to check for alerts. -m 1 checks for alerts of Medium severity or above and -a causes zap-cli to fail if alerts are found.
  • artifacts: is used to store the report, and make it accessible from the GitLab UI.

Considerations

  • If your app uses authentication, you may need to configure ZAP to handle it using context files, Zest scripts, or cli options.
  • If you need a more advanced scan, consider using the zap-full-scan.py script instead of zap-baseline.py.
  • Use environment variables to manage sensitive data like API keys.

Conclusion

OWASP ZAP is a powerful and versatile tool for implementing automated DAST within your CI/CD pipeline. By integrating ZAP early and configuring it effectively, you can proactively identify and address vulnerabilities in your web applications before they reach production. Thereby reducing your security risk, improving your application's security posture, and helps you build more secure software. Remember that security is always about continuous improvement. Using OWASP ZAP in your CI/CD pipeline is a significant step toward achieving a more secure development lifecycle.