Unsecured Backend Services in Google Cloud Load Balancers

ID: gcloud-lb-backend-unsecured

Severity: medium

Author: princechaddha

Tags: cloud,devops,gcp,gcloud,google-cloud-load-balancer,gcp-cloud-config

Description

Ensure that the backend services associated with your Google Cloud load balancers are protected with edge security policies provided by the Cloud Armor service in order to shield your backend services from a range of potential attacks. Edge security policies let you control access to your cloud resources at the Google Cloud Platform (GCP) network edge.

YAML Source

id: gcloud-lb-backend-unsecured

info:
  name: Unsecured Backend Services in Google Cloud Load Balancers
  author: princechaddha
  severity: medium
  description: |
    Ensure that the backend services associated with your Google Cloud load balancers are protected with edge security policies provided by the Cloud Armor service in order to shield your backend services from a range of potential attacks. Edge security policies let you control access to your cloud resources at the Google Cloud Platform (GCP) network edge.
  impact: |
    Without edge security policies, backend services are vulnerable to a variety of network-based attacks, which can compromise data integrity and availability.
  remediation: |
    Attach an edge security policy to your backend services via the Google Cloud Console or using the Cloud Armor APIs to enhance security at your network's edge.
  reference:
    - https://cloud.google.com/armor/docs/security-policy-overview
  tags: cloud,devops,gcp,gcloud,google-cloud-load-balancer,gcp-cloud-config

flow: |
  code(1)
  for(let projectId of iterate(template.projectIds)){
    set("projectId", projectId)
    code(2)
    for(let urlMapName of iterate(template.urlMaps)){
      set("urlMapName", urlMapName)
      code(3)
      for(let backendService of iterate(template.backendServices)){
        set("backendService", backendService)
        code(4)
      }
    }
  }

self-contained: true

code:
  - engine:
      - sh
      - bash
    source: |
      gcloud projects list --format="json(projectId)"

    extractors:
      - type: json
        name: projectIds
        internal: true
        json:
          - '.[].projectId'

  - engine:
      - sh
      - bash
    source: |
      gcloud compute url-maps list --project $projectId --format="json(name)"

    extractors:
      - type: json
        name: urlMaps
        internal: true
        json:
          - '.[].name'

  - engine:
      - sh
      - bash
    source: |
      gcloud compute url-maps describe $urlMapName --format="json(defaultService)"

    extractors:
      - type: json
        name: backendServices
        internal: true
        json:
          - '.defaultService'

  - engine:
      - sh
      - bash
    source: |
      gcloud compute backend-services describe $backendService --format="json(securityPolicy)"

    matchers:
      - type: word
        words:
          - 'null'

    extractors:
      - type: dsl
        dsl:
          - '"Unsecured Backend Service " + backendService + " for URL Map " + urlMapName + " in Project " + projectId'
# digest: 490a004630440220279358e65ac5b963edec13c94cb6c092c5cd7bb5efc2d6556cf1a14174d428060220347ee3311f47662b5d3cdf9870d49478b018f98ddf6703f283187f7878c26d69:922c64590222798bb761d5b6d8e72950

Guide to check the vulnerabilities

This template is used to detect vulnerabilities in web applications. It can be used with the Nuclei tool to scan for specific patterns or behaviors.

$ nuclei -u "URL" -t "cloud/gcp/loadbalancing/gcloud-lb-backend-unsecured.yaml"

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