AWSOverview
Overview
The S3 bucket policy access permission settings are used to define who can access data and objects contained in a bucket. Users with access to S3 buckets are authorized to read, write, upload and delete objects and data in the bucket. This level of permission granted to Everyone may result in theft of data, compromised privacy, or unintended charges.
Remediation guidance
AWS remediation
Console
- Open S3 bucket permissions.
- Remove bucket policy statements that allow broad public principals.
- Keep Block Public Access enabled.
AWS CLI
aws s3api put-public-access-block \
--bucket <bucket-name> \
--public-access-block-configuration 'BlockPublicAcls=true,IgnorePublicAcls=true,BlockPublicPolicy=true,RestrictPublicBuckets=true'
References
- https://docs.aws.amazon.com/AmazonS3/latest/userguide/access-policy-alternatives-guidelines.html
- https://docs.aws.amazon.com/cli/latest/reference/s3api/put-public-access-block.html
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.
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.
S3 bucket policy does not grant Allow permission to everyone
Connectors
Covered asset types
Expected check: eq []
{buckets(where:{AND:[{policyDocument_CONTAINS:"\"Effect\":\"Allow\""},{policyDocument_CONTAINS:"\"Principal\":\"*\""}]}){...AssetFragment}}
