gcloud-org-uniform-bucket-access: Uniform Bucket-Level Access Not Enforced

id: gcloud-org-uniform-bucket-access

info:
  name: Uniform Bucket-Level Access Not Enforced
  author: princechaddha
  severity: medium
  description: |
    Ensure that "Enforce uniform bucket-level access" policy is enabled for your Google Cloud Platform (GCP) organization in order to enforce uniform bucket-level access for all Google Cloud Storage buckets available in your organization. Enforcing uniform bucket-level access disables Access Control Lists (ACLs) for all Cloud Storage resources (buckets and objects) so that access is granted exclusively through Cloud IAM service.
  impact: |
    Without enforced uniform bucket-level access, buckets may use legacy ACLs which are less secure and more complex to manage than Cloud IAM permissions, potentially leading to misconfigured access controls.
  remediation: |
    Enable the "Enforce uniform bucket-level access" policy at the organization level using the 'gcloud alpha resource-manager org-policies enable-enforce' command with the storage.uniformBucketLevelAccess constraint.
  reference:
    - https://www.trendmicro.com/cloudoneconformity/knowledge-base/gcp/ResourceManager/enforce-uniform-bucket-level-access-constraint.html
    - https://cloud.google.com/storage/docs/uniform-bucket-level-access
  tags: cloud,devops,gcp,gcloud,resourcemanager,security,storage,bucket,gcp-cloud-config

flow: |
  code(1)
  for(let orgId of iterate(template.orgIds)){
    set("orgId", orgId)
    code(2)
  }

self-contained: true

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

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

  - engine:
      - sh
      - bash
    source: |
      gcloud alpha resource-manager org-policies describe storage.uniformBucketLevelAccess --organization=$orgId --effective --format="json(booleanPolicy)"

    matchers:
      - type: word
        words:
          - "{}"

    extractors:
      - type: dsl
        dsl:
          - '"Organization " + orgId + " has not enforced uniform bucket-level access for Cloud Storage buckets"'
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