Alibaba Cloud
AWS
Google CloudOverview
Publicly writable buckets allow anyone to upload, modify, and/or delete data from your buckets. This can lead to data loss, malware spread, and increased costs.
If you indeed want to allow your users to upload objects to your buckets, you can either let your application handle it or you (your application) can generate signed URLs granting the permission for a certain action at a certain path:
AWS
Google Cloud
Alibaba
Remediation guidance
AWS
- https://docs.aws.amazon.com/AmazonS3/latest/userguide/access-control-block-public-access.html
Google Cloud
- https://cloud.google.com/storage/docs/access-control#public_access_prevention
Alibaba Cloud
- https://www.alibabacloud.com/help/en/object-storage-service/latest/access-and-control-overview
Service-wide remediation
Recommended when many resources are affected: fix the platform baseline first so new resources inherit the secure setting, then remediate the existing flagged resources in batches.
AWS
Use AWS Organizations guardrails, AWS Config rules or conformance packs where they fit, approved account baselines, and IaC modules so new resources inherit the secure setting.
Google Cloud
Use organization or folder policies where available, shared project templates, logs and alerting baselines, and IaC modules so new resources inherit the secure setting.
Alibaba Cloud
Use Resource Directory guardrails, account baselines, and IaC modules so the secure setting is applied consistently across environments.
Operational rollout
- Fix the baseline first at the account, subscription, project, cluster, or tenant scope that owns this control.
- Remediate the currently affected resources in batches, starting with internet-exposed and production assets.
- Re-scan and track approved exceptions with an owner and expiry date.
Query logic
These are the stored checks tied to this control.
Publicly Writable AWS Buckets
Connectors
Covered asset types
Expected check: eq []
{ buckets( where: { cloudProvider: "aws" publicAccessBlocked: false OR: [ { hasBucketACLGrant_SOME: { OR: [ { granteeURI: "http://acs.amazonaws.com/groups/global/AllUsers" } { granteeURI: "http://acs.amazonaws.com/groups/global/AuthenticatedUsers" } ] permission_IN: ["WRITE", "WRITE_ACP", "FULL_CONTROL"] } } { bucketPolicy: { AND: [ { statements_SOME: { effect: "Allow" OR: [ { actions_INCLUDES: "s3:PutObject" } { actions_INCLUDES: "s3:PutObjectAcl" } { actions_INCLUDES: "s3:CreateMultipartUpload" } { actions_INCLUDES: "s3:UploadPart" } { actions_INCLUDES: "s3:DeleteObject" } { actions_INCLUDES: "s3:DeleteObjects" } { actions_INCLUDES: "s3:*" } { actions_INCLUDES: "*" } ] principals_INCLUDES: "AWS|*" } } ] } } ] } ) {...AssetFragment} } Publicly Writable Google Cloud Buckets
Connectors
Covered asset types
Expected check: eq []
{ buckets( where: { cloudProvider: "gcp" publicAccessBlocked: false iamBindings_SOME: { OR: [ { members_INCLUDES: "allUsers" } { members_INCLUDES: "allAuthenticatedUsers" } ] role: { OR: [ { permissions_INCLUDES: "storage.objects.create" } { permissions_INCLUDES: "storage.objects.delete" } { permissions_INCLUDES: "storage.objects.update" } { permissions_INCLUDES: "storage.objects.setIamPolicy" } { permissions_INCLUDES: "storage.multipartUploads.create" } { permissions_INCLUDES: "storage.objects.*" } { permissions_INCLUDES: "storage.multipartUploads.*" } ] } } } ) {...AssetFragment} } Publicly Writable Alibaba Buckets
Connectors
Covered asset types
Expected check: eq []
{ buckets( where: { cloudProvider: "alibaba" publicAccessBlocked: false OR: [ { acl_IN: ["public-read-write"] } { bucketPolicy: { statements_SOME: { effect: "Allow" OR: [ { actions_INCLUDES: "oss:PutObject" } { actions_INCLUDES: "oss:PutObjectAcl" } { actions_INCLUDES: "oss:*" } { actions_INCLUDES: "*" } ] principals_INCLUDES: "*" } } } ] } ) {...AssetFragment} } 
