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🛡️ AWS S3 Access Point is not configured to block public access🟢

Logic​

Similar Policies​

Description​

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Description​

This policy identifies AWS S3 Access Points that are not configured to block all public access.

Amazon S3 Access Points simplify managing data access at scale for shared datasets stored in S3. Each access point has its own permissions and network controls, including Block Public Access settings. These settings provide an additional security layer to prevent accidental public exposure of data through the access point.

Rationale​

Keeping Block Public Access settings enabled for S3 Access Points ensures that, regardless of the underlying bucket policies or object ACLs, the access point will reject all public requests. This helps prevent data leaks caused by misconfigurations and enforces a strict boundary against unauthorized public access.

Audit​

This policy flags an AWS S3 Access Point as INCOMPLIANT if any of the following settings are not set to Yes:

  • Block Public ACLs
  • Block Public Policy
  • Ignore Public ACLs
  • Restrict Public Buckets

Remediation​

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Remediation​

Enable Block Public Access for S3 Access Points​

The Block Public Access settings for an S3 Access Point are immutable and cannot be modified after the access point is created. To remediate this issue, you must create a new access point with the correct configuration and migrate all dependencies from the incompliant one.

Remediation Steps​

  1. Create a new S3 Access Point

    Use the following command to create a new access point with all public access blocked. Ensure that the --public-access-block-configuration parameter includes all four blocking options set to true:

    aws s3control create-access-point \
        --account-id {{account-id}} \
        --name {{new-access-point-name}} \
        --bucket {{bucket-name}} \
        --public-access-block-configuration "BlockPublicAcls=true,IgnorePublicAcls=true,BlockPublicPolicy=true,RestrictPublicBuckets=true"

  2. Update All References to the New Access Point

    Update all dependent resources to use the ARN of the new access point instead of the old one.

... see more

policy.yaml​

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Linked Framework Sections​

SectionSub SectionsInternal RulesPoliciesFlagsCompliance
💼 AWS Foundational Security Best Practices v1.0.0 → 💼 [S3.19] S3 access points should have block public access settings enabled1no data
💼 AWS Well-Architected → 💼 SEC08-BP04 Enforce access control7no data
💼 Cloudaware Framework → 💼 Public and Anonymous Access106no data
💼 FedRAMP High Security Controls → 💼 AC-3 Access Enforcement (L)(M)(H)3772no data
💼 FedRAMP High Security Controls → 💼 AC-4 Information Flow Enforcement (M)(H)23789no data
💼 FedRAMP High Security Controls → 💼 AC-4(21) Physical or Logical Separation of Information Flows (M)(H)1152no data
💼 FedRAMP High Security Controls → 💼 AC-6 Least Privilege (M)(H)81161no data
💼 FedRAMP High Security Controls → 💼 AC-21 Information Sharing (M)(H)12no data
💼 FedRAMP High Security Controls → 💼 SC-7 Boundary Protection (L)(M)(H)10864no data
💼 FedRAMP High Security Controls → 💼 SC-7(3) Access Points (M)(H)12no data
💼 FedRAMP High Security Controls → 💼 SC-7(4) External Telecommunications Services (M)(H)35no data
💼 FedRAMP High Security Controls → 💼 SC-7(20) Dynamic Isolation and Segregation (H)12no data
💼 FedRAMP High Security Controls → 💼 SC-7(21) Isolation of System Components (H)28no data
💼 FedRAMP Low Security Controls → 💼 AC-3 Access Enforcement (L)(M)(H)72no data
💼 FedRAMP Low Security Controls → 💼 SC-7 Boundary Protection (L)(M)(H)40no data
💼 FedRAMP Moderate Security Controls → 💼 AC-3 Access Enforcement (L)(M)(H)72no data
💼 FedRAMP Moderate Security Controls → 💼 AC-4 Information Flow Enforcement (M)(H)173no data
💼 FedRAMP Moderate Security Controls → 💼 AC-4(21) Physical or Logical Separation of Information Flows (M)(H)52no data
💼 FedRAMP Moderate Security Controls → 💼 AC-6 Least Privilege (M)(H)661no data
💼 FedRAMP Moderate Security Controls → 💼 AC-21 Information Sharing (M)(H)12no data
💼 FedRAMP Moderate Security Controls → 💼 SC-7 Boundary Protection (L)(M)(H)753no data
💼 FedRAMP Moderate Security Controls → 💼 SC-7(3) Access Points (M)(H)12no data
💼 FedRAMP Moderate Security Controls → 💼 SC-7(4) External Telecommunications Services (M)(H)35no data
💼 NIST CSF v2.0 → 💼 DE.CM-01: Networks and network services are monitored to find potentially adverse events150no data
💼 NIST CSF v2.0 → 💼 DE.CM-09: Computing hardware and software, runtime environments, and their data are monitored to find potentially adverse events149no data
💼 NIST CSF v2.0 → 💼 ID.AM-03: Representations of the organization's authorized network communication and internal and external network data flows are maintained76no data
💼 NIST CSF v2.0 → 💼 PR.AA-05: Access permissions, entitlements, and authorizations are defined in a policy, managed, enforced, and reviewed, and incorporate the principles of least privilege and separation of duties120no data
💼 NIST CSF v2.0 → 💼 PR.DS-01: The confidentiality, integrity, and availability of data-at-rest are protected164no data
💼 NIST CSF v2.0 → 💼 PR.DS-02: The confidentiality, integrity, and availability of data-in-transit are protected140no data
💼 NIST CSF v2.0 → 💼 PR.DS-10: The confidentiality, integrity, and availability of data-in-use are protected156no data
💼 NIST CSF v2.0 → 💼 PR.IR-01: Networks and environments are protected from unauthorized logical access and usage103no data
💼 NIST SP 800-53 Revision 5 → 💼 AC-3 Access Enforcement15544no data
💼 NIST SP 800-53 Revision 5 → 💼 AC-3(7) Access Enforcement _ Role-based Access Control18no data
💼 NIST SP 800-53 Revision 5 → 💼 AC-4 Information Flow Enforcement326999no data
💼 NIST SP 800-53 Revision 5 → 💼 AC-4(21) Information Flow Enforcement _ Physical or Logical Separation of Information Flows3752no data
💼 NIST SP 800-53 Revision 5 → 💼 AC-6 Least Privilege102354no data
💼 NIST SP 800-53 Revision 5 → 💼 AC-21 Information Sharing212no data
💼 NIST SP 800-53 Revision 5 → 💼 SC-7 Boundary Protection29466no data
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(3) Boundary Protection _ Access Points12no data
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(4) Boundary Protection _ External Telecommunications Services35no data
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(9) Boundary Protection _ Restrict Threatening Outgoing Communications Traffic18no data
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(11) Boundary Protection _ Restrict Incoming Communications Traffic28no data
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(16) Boundary Protection _ Prevent Discovery of System Components29no data
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(20) Boundary Protection _ Dynamic Isolation and Segregation12no data
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(21) Boundary Protection _ Isolation of System Components28no data
💼 PCI DSS v3.2.1 → 💼 1.3.6 Place system components that store cardholder data in an internal network zone, segregated from the DMZ and other untrusted networks.11no data
💼 PCI DSS v4.0.1 → 💼 1.4.4 System components that store cardholder data are not directly accessible from untrusted networks.11no data
💼 PCI DSS v4.0 → 💼 1.4.4 System components that store cardholder data are not directly accessible from untrusted networks.11no data