Dynamic Application Security Testing (DAST)

If you deploy your web application into a new environment, your application may become exposed to new types of attacks. For example, misconfigurations of your application server or incorrect assumptions about security controls may not be visible from the source code.

Dynamic Application Security Testing (DAST) examines applications for vulnerabilities like these in deployed environments.

For an overview, see Dynamic Application Security Testing (DAST).

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GitLab DAST

GitLab provides the following DAST analyzers, one or more of which may be useful depending on the kind of application you’re testing.

For scanning websites, use one of:

  • The DAST proxy-based analyzer for scanning traditional applications serving simple HTML. The proxy-based analyzer can be run automatically or on-demand.
  • The DAST browser-based analyzer for scanning applications that make heavy use of JavaScript. This includes single page web applications.

For scanning APIs, use:

  • The DAST API analyzer for scanning web APIs. Web API technologies such as GraphQL, REST, and SOAP are supported.

Analyzers follow the architectural patterns described in Secure your application. Each analyzer can be configured in the pipeline using a CI template and runs the scan in a Docker container. Scans output a DAST report artifact which GitLab uses to determine discovered vulnerabilities based on differences between scan results on the source and target branches.

Getting started

Prerequisites

  • GitLab Runner available, with the docker executor on Linux/amd64.
  • Target application deployed. For more details, read Deployment options.
  • dast stage added to the CI/CD pipeline definition. This should be added after the deploy step, for example:

    stages:
      - build
      - test
      - deploy
      - dast
    

Recommendations

  • Take care if your pipeline is configured to deploy to the same web server in each run. Running a DAST scan while a server is being updated leads to inaccurate and non-deterministic results.
  • Configure runners to use the always pull policy to run the latest versions of the analyzers.
  • By default, DAST downloads all artifacts defined by previous jobs in the pipeline. If your DAST job does not rely on environment_url.txt to define the URL under test or any other files created in previous jobs, we recommend you don’t download artifacts. To avoid downloading artifacts, extend the analyzer CI/CD job to specify no dependencies. For example, for the DAST proxy-based analyzer add the following to your .gitlab-ci.yml file:

    dast:
      dependencies: []
    

Analyzer configuration

See DAST proxy-based analyzer, DAST browser-based analyzer or DAST API analyzer for analyzer-specific configuration instructions.

View scan results

Introduced in GitLab 13.1.

Detected vulnerabilities appear in merge requests, the pipeline security tab, and the vulnerability report.

  1. To see all vulnerabilities detected, either:
    • From your project, select Security & Compliance, then Vulnerability report.
    • From your pipeline, select the Security tab.
    • From the merge request, go to the Security scanning widget and select Full report tab.
  2. Select a DAST vulnerability’s description. The following fields are examples of what a DAST analyzer may produce to aid investigation and rectification of the underlying cause. Each analyzer may output different fields.

    FieldDescription
    DescriptionDescription of the vulnerability.
    EvidenceEvidence of the data found that verified the vulnerability. Often a snippet of the request or response, this can be used to help verify that the finding is a vulnerability.
    IdentifiersIdentifiers of the vulnerability.
    LinksLinks to further details of the detected vulnerability.
    MethodHTTP method used to detect the vulnerability.
    ProjectNamespace and project in which the vulnerability was detected.
    Request HeadersHeaders of the request.
    Response HeadersHeaders of the response received from the application.
    Response StatusResponse status received from the application.
    Scanner TypeType of vulnerability report.
    SeveritySeverity of the vulnerability.
    SolutionDetails of a recommended solution to the vulnerability.
    URLURL at which the vulnerability was detected.
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A pipeline may consist of multiple jobs, including SAST and DAST scanning. If any job fails to finish for any reason, the security dashboard doesn’t show DAST scanner output. For example, if the DAST job finishes but the SAST job fails, the security dashboard doesn’t show DAST results. On failure, the analyzer outputs an exit code.

List URLs scanned

When DAST completes scanning, the merge request page states the number of URLs scanned. Select View details to view the web console output which includes the list of scanned URLs.

DAST Widget

Application deployment options

DAST requires a deployed application to be available to scan.

Depending on the complexity of the target application, there are a few options as to how to deploy and configure the DAST template. A set of example applications have been provided with their configurations in the DAST demonstrations project.

Review Apps

Review Apps are the most involved method of deploying your DAST target application. To assist in the process, we created a Review App deployment using Google Kubernetes Engine (GKE). This example can be found in our Review Apps - GKE project, along with detailed instructions in the README.md on how to configure Review Apps for DAST.

Docker Services

If your application uses Docker containers you have another option for deploying and scanning with DAST. After your Docker build job completes and your image is added to your container registry, you can use the image as a service.

By using service definitions in your .gitlab-ci.yml, you can scan services with the DAST analyzer.

When adding a services section to the job, the alias is used to define the hostname that can be used to access the service. In the following example, the alias: yourapp portion of the dast job definition means that the URL to the deployed application uses yourapp as the hostname (https://yourapp/).

stages:
  - build
  - dast

include:
  - template: DAST.gitlab-ci.yml

# Deploys the container to the GitLab container registry
deploy:
  services:
  - name: docker:dind
    alias: dind
  image: docker:20.10.16
  stage: build
  script:
    - docker login -u gitlab-ci-token -p $CI_JOB_TOKEN $CI_REGISTRY
    - docker pull $CI_REGISTRY_IMAGE:latest || true
    - docker build --tag $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA --tag $CI_REGISTRY_IMAGE:latest .
    - docker push $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
    - docker push $CI_REGISTRY_IMAGE:latest

dast:
  services: # use services to link your app container to the dast job
    - name: $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
      alias: yourapp

variables:
  DAST_WEBSITE: https://yourapp
  DAST_FULL_SCAN_ENABLED: "true" # do a full scan
  DAST_BROWSER_SCAN: "true" # use the browser-based GitLab DAST crawler

Most applications depend on multiple services such as databases or caching services. By default, services defined in the services fields cannot communicate with each another. To allow communication between services, enable the FF_NETWORK_PER_BUILD feature flag.

variables:
  FF_NETWORK_PER_BUILD: "true" # enable network per build so all services can communicate on the same network

services: # use services to link the container to the dast job
  - name: mongo:latest
    alias: mongo
  - name: $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA
    alias: yourapp