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📝 AWS S3 Bucket is not configured to block public access 🟢

  • Contextual name: 📝 Bucket is not configured to block public access 🟢
  • ID: /ce/ca/aws/s3/bucket-block-public-access
  • Located in: 📁 AWS S3

Flags​

Our Metadata​

  • Policy Type: COMPLIANCE_POLICY
  • Policy Category:
    • SECURITY

Similar Policies​

Similar Internal Rules​

RulePoliciesFlags
✉️ dec-x-ec547a7c1

Logic​

Description​

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Description​

Amazon S3 provides Block public access (bucket settings) and Block public access (account settings) to help you manage public access to Amazon S3 resources. By default, S3 buckets and objects are created with public access disabled. However, an IAM principal with sufficient S3 permissions can enable public access at the bucket and/or object level. While enabled, Block public access (bucket settings) prevents an individual bucket, and its contained objects, from becoming publicly accessible. Similarly, Block public access (account settings) prevents all buckets, and contained objects, from becoming publicly accessible across the entire account.

Rationale​

Amazon S3 Block public access (bucket settings) prevents the accidental or malicious public exposure of data contained within the respective bucket(s).

Amazon S3 Block public access (account settings) prevents the accidental or malicious public exposure of data contained within all buckets of the respective AWS account.

Whether blocking public access to all or some buckets is an organizational decision that should be based on data sensitivity, least privilege, and use case.

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Remediation​

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Remediation​

If utilizing Block Public Access (bucket settings)​

Using AWS CloudFormation​
  • CloudFormation template (YAML):
AWSTemplateFormatVersion: '2010-09-09'
Description: Enables block public access settings on an existing S3 bucket.

Parameters:
  BucketName:
    Type: String
    Description: Name of the existing S3 bucket

Resources:
  BlockPublicAccess:
    Type: AWS::S3::Bucket
    Properties:
      BucketName: !Ref BucketName
      PublicAccessBlockConfiguration:
        BlockPublicAcls: true
        IgnorePublicAcls: true
        BlockPublicPolicy: true
        RestrictPublicBuckets: true
From Console​
  1. Login to AWS Management Console and open the Amazon S3 console using https://console.aws.amazon.com/s3/.
  2. Select the Check box next to the Bucket.
  3. Click on Edit public access settings.
  4. Click Block all public access.
  5. Repeat for all the buckets in your AWS account that contain sensitive data.
From Command Line​
  1. List all of the S3 Buckets:
aws s3 ls
  1. Set the Block Public Access to true on that bucket:

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policy.yaml​

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Linked Framework Sections​

SectionSub SectionsInternal RulesPoliciesFlags
💼 APRA CPG 234 → 💼 36d access management controls —only authorised users, software and hardware are able to access information assets (refer to Attachment B for further guidance);1415
💼 APRA CPG 234 → 💼 36e hardware and software asset controls —appropriate authorisation to prevent security compromises from unauthorised hardware and software assets;1617
💼 APRA CPG 234 → 💼 36f network design — to ensure authorised network traffic flows and to reduce the impact of security compromises;2729
💼 APRA CPG 234 → 💼 45 An understanding of plausible worst case scenarios can help regulated entities identify and implement additional controls to prevent or reduce the impact of such scenarios. One example is malware that infects computers and encrypts data, both on the infected computer and any connected storage, including (corporate) networks and cloud storage. Such attacks reinforce the importance of protecting the backup environment in the event that the production environment is compromised. Common techniques to achieve this include network segmentation, highly restricted and segregated access controls and network traffic flow restrictions.3336
💼 APRA CPG 234 → 💼 52d appropriate segmentation of data, based on sensitivity and access needs;1010
💼 APRA CPG 234 → 💼 53 Wholesale access to sensitive data (e.g. contents of customer databases or intellectual property that can be exploited for personal gain) would be highly restricted to reduce the risk exposure to significant data leakage events. Industry experience of actual data leakage incidents include the unauthorised extraction of debit/credit card details, theft of personally identifiable information, loss of unencrypted backup media and the sale/trade or exploitation of customer identity data.1010
💼 AWS Foundational Security Best Practices v1.0.0 → 💼 [S3.1] S3 general purpose buckets should have block public access settings enabled1
💼 CIS AWS v1.3.0 → 💼 1.20 Ensure that S3 Buckets are configured with 'Block public access (bucket settings)'11
💼 CIS AWS v1.4.0 → 💼 2.1.5 Ensure that S3 Buckets are configured with 'Block public access (bucket settings)'11
💼 CIS AWS v1.5.0 → 💼 2.1.5 Ensure that S3 Buckets are configured with 'Block public access (bucket settings)' - Level 1 (Automated)11
💼 CIS AWS v2.0.0 → 💼 2.1.4 Ensure that S3 Buckets are configured with 'Block public access (bucket settings)' - Level 1 (Automated)11
💼 CIS AWS v3.0.0 → 💼 2.1.4 Ensure that S3 Buckets are configured with 'Block public access (bucket settings)' - Level 1 (Automated)11
💼 CIS AWS v4.0.0 → 💼 2.1.4 Ensure that S3 is configured with 'Block Public Access' enabled (Automated)1
💼 CIS AWS v4.0.1 → 💼 2.1.4 Ensure that S3 is configured with 'Block Public Access' enabled (Automated)1
💼 CIS AWS v5.0.0 → 💼 2.1.4 Ensure that S3 is configured with 'Block Public Access' enabled (Automated)1
💼 Cloudaware Framework → 💼 Public and Anonymous Access72
💼 FedRAMP High Security Controls → 💼 AC-3 Access Enforcement (L)(M)(H)3763
💼 FedRAMP High Security Controls → 💼 AC-4 Information Flow Enforcement (M)(H)23471
💼 FedRAMP High Security Controls → 💼 AC-4(21) Physical or Logical Separation of Information Flows (M)(H)1140
💼 FedRAMP High Security Controls → 💼 AC-6 Least Privilege (M)(H)81150
💼 FedRAMP High Security Controls → 💼 AC-21 Information Sharing (M)(H)3
💼 FedRAMP High Security Controls → 💼 SC-7 Boundary Protection (L)(M)(H)10840
💼 FedRAMP High Security Controls → 💼 SC-7(3) Access Points (M)(H)3
💼 FedRAMP High Security Controls → 💼 SC-7(4) External Telecommunications Services (M)(H)22
💼 FedRAMP High Security Controls → 💼 SC-7(20) Dynamic Isolation and Segregation (H)3
💼 FedRAMP High Security Controls → 💼 SC-7(21) Isolation of System Components (H)17
💼 FedRAMP Low Security Controls → 💼 AC-3 Access Enforcement (L)(M)(H)63
💼 FedRAMP Low Security Controls → 💼 SC-7 Boundary Protection (L)(M)(H)28
💼 FedRAMP Moderate Security Controls → 💼 AC-3 Access Enforcement (L)(M)(H)63
💼 FedRAMP Moderate Security Controls → 💼 AC-4 Information Flow Enforcement (M)(H)157
💼 FedRAMP Moderate Security Controls → 💼 AC-4(21) Physical or Logical Separation of Information Flows (M)(H)40
💼 FedRAMP Moderate Security Controls → 💼 AC-6 Least Privilege (M)(H)650
💼 FedRAMP Moderate Security Controls → 💼 AC-21 Information Sharing (M)(H)3
💼 FedRAMP Moderate Security Controls → 💼 SC-7 Boundary Protection (L)(M)(H)736
💼 FedRAMP Moderate Security Controls → 💼 SC-7(3) Access Points (M)(H)3
💼 FedRAMP Moderate Security Controls → 💼 SC-7(4) External Telecommunications Services (M)(H)22
💼 ISO/IEC 27001:2013 → 💼 A.9.4.1 Information access restriction1719
💼 ISO/IEC 27001:2022 → 💼 5.10 Acceptable use of information and other associated assets1126
💼 ISO/IEC 27001:2022 → 💼 5.15 Access control1430
💼 ISO/IEC 27001:2022 → 💼 8.3 Information access restriction1023
💼 ISO/IEC 27001:2022 → 💼 8.4 Access to source code821
💼 NIST CSF v1.1 → 💼 DE.CM-1: The network is monitored to detect potential cybersecurity events1942
💼 NIST CSF v1.1 → 💼 PR.AC-4: Access permissions and authorizations are managed, incorporating the principles of least privilege and separation of duties1551
💼 NIST CSF v1.1 → 💼 PR.AC-5: Network integrity is protected (e.g., network segregation, network segmentation)921
💼 NIST CSF v1.1 → 💼 PR.DS-2: Data-in-transit is protected1630
💼 NIST CSF v1.1 → 💼 PR.DS-5: Protections against data leaks are implemented4464
💼 NIST CSF v1.1 → 💼 PR.IP-1: A baseline configuration of information technology/industrial control systems is created and maintained incorporating security principles (e.g. concept of least functionality)225
💼 NIST CSF v1.1 → 💼 PR.PT-3: The principle of least functionality is incorporated by configuring systems to provide only essential capabilities2130
💼 NIST CSF v1.1 → 💼 PR.PT-4: Communications and control networks are protected921
💼 NIST CSF v2.0 → 💼 DE.CM-01: Networks and network services are monitored to find potentially adverse events111
💼 NIST CSF v2.0 → 💼 DE.CM-09: Computing hardware and software, runtime environments, and their data are monitored to find potentially adverse events129
💼 NIST CSF v2.0 → 💼 ID.AM-03: Representations of the organization's authorized network communication and internal and external network data flows are maintained43
💼 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 duties86
💼 NIST CSF v2.0 → 💼 PR.AA-06: Physical access to assets is managed, monitored, and enforced commensurate with risk21
💼 NIST CSF v2.0 → 💼 PR.DS-01: The confidentiality, integrity, and availability of data-at-rest are protected107
💼 NIST CSF v2.0 → 💼 PR.DS-02: The confidentiality, integrity, and availability of data-in-transit are protected89
💼 NIST CSF v2.0 → 💼 PR.DS-10: The confidentiality, integrity, and availability of data-in-use are protected102
💼 NIST CSF v2.0 → 💼 PR.IR-01: Networks and environments are protected from unauthorized logical access and usage63
💼 NIST SP 800-53 Revision 4 → 💼 CM-7 (1) PERIODIC REVIEW34
💼 NIST SP 800-53 Revision 4 → 💼 CM-7 LEAST FUNCTIONALITY567
💼 NIST SP 800-53 Revision 4 → 💼 SC-7 BOUNDARY PROTECTION23510
💼 NIST SP 800-53 Revision 4 → 💼 SC-8 TRANSMISSION CONFIDENTIALITY AND INTEGRITY422
💼 NIST SP 800-53 Revision 5 → 💼 AC-3 Access Enforcement15532
💼 NIST SP 800-53 Revision 5 → 💼 AC-3(7) Access Enforcement _ Role-based Access Control9
💼 NIST SP 800-53 Revision 5 → 💼 AC-4 Information Flow Enforcement326480
💼 NIST SP 800-53 Revision 5 → 💼 AC-4(15) Information Flow Enforcement _ Detection of Unsanctioned Information89
💼 NIST SP 800-53 Revision 5 → 💼 AC-4(21) Information Flow Enforcement _ Physical or Logical Separation of Information Flows3540
💼 NIST SP 800-53 Revision 5 → 💼 AC-6 Least Privilege102343
💼 NIST SP 800-53 Revision 5 → 💼 AC-21 Information Sharing23
💼 NIST SP 800-53 Revision 5 → 💼 SC-7 Boundary Protection29341
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(3) Boundary Protection _ Access Points3
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(4) Boundary Protection _ External Telecommunications Services22
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(9) Boundary Protection _ Restrict Threatening Outgoing Communications Traffic9
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(11) Boundary Protection _ Restrict Incoming Communications Traffic17
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(16) Boundary Protection _ Prevent Discovery of System Components18
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(20) Boundary Protection _ Dynamic Isolation and Segregation3
💼 NIST SP 800-53 Revision 5 → 💼 SC-7(21) Boundary Protection _ Isolation of System Components17
💼 PCI DSS v3.2.1 → 💼 1.2.1 Restrict inbound and outbound traffic to that which is necessary for the cardholder data environment, and specifically deny all other traffic.1027
💼 PCI DSS v3.2.1 → 💼 1.3 Prohibit direct public access between the Internet and any system component in the cardholder data environment.7718
💼 PCI DSS v3.2.1 → 💼 1.3.1 Implement a DMZ to limit inbound traffic to only system components that provide authorized publicly accessible services, protocols, and ports.512
💼 PCI DSS v3.2.1 → 💼 1.3.2 Limit inbound Internet traffic to IP addresses within the DMZ.12
💼 PCI DSS v3.2.1 → 💼 1.3.4 Do not allow unauthorized outbound traffic from the cardholder data environment to the Internet.4
💼 PCI DSS v3.2.1 → 💼 1.3.5 Permit only “established” connections into the network.12
💼 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.4
💼 PCI DSS v4.0.1 → 💼 1.3.1 Inbound traffic to the CDE is restricted.27
💼 PCI DSS v4.0.1 → 💼 1.3.2 Outbound traffic from the CDE is restricted.27
💼 PCI DSS v4.0.1 → 💼 1.4.1 NSCs are implemented between trusted and untrusted networks.11
💼 PCI DSS v4.0.1 → 💼 1.4.2 Inbound traffic from untrusted networks to trusted networks is restricted.12
💼 PCI DSS v4.0.1 → 💼 1.4.4 System components that store cardholder data are not directly accessible from untrusted networks.4
💼 PCI DSS v4.0 → 💼 1.3.1 Inbound traffic to the CDE is restricted.27
💼 PCI DSS v4.0 → 💼 1.3.2 Outbound traffic from the CDE is restricted.27
💼 PCI DSS v4.0 → 💼 1.4.1 NSCs are implemented between trusted and untrusted networks.11
💼 PCI DSS v4.0 → 💼 1.4.2 Inbound traffic from untrusted networks to trusted networks is restricted.12
💼 PCI DSS v4.0 → 💼 1.4.4 System components that store cardholder data are not directly accessible from untrusted networks.4
💼 SOC 2 → 💼 CC7.1-1 Uses Defined Configuration Standards45
💼 UK Cyber Essentials → 💼 1.2 Prevent access to the administrative interface from the internet3437