📝 Azure Storage Account Allow Blob Anonymous Access is set enabled 🟢

• Contextual name: 📝 Allow Blob Anonymous Access is set enabled 🟢
• ID: /ce/ca/azure/storage/disable-allow-blob-anonymous-access
• Located in: 📁 Azure Storage

Flags

• 🟢 Policy with categories
• 🟢 Policy with type
• 🟢 Production policy

Our Metadata

• Policy Type: COMPLIANCE_POLICY
• Policy Category:
  • SECURITY

Similar Policies

• Cloud Conformity
  • Disable public access to storage accounts with blob containers
• Internal
  • dec-x-083928f5

Similar Internal Rules

Rule	Policies	Flags
✉️ dec-x-083928f5	1

Logic

• 🧠 prod.logic.yaml 🟢
  • 📕 Azure Storage Account
  • 🔌 Azure Storage Account - object.extracts.yaml
  • 🧪 test-data.json

Description

Open File

Description

The Azure Storage setting ‘Allow Blob Anonymous Access’ (aka "allowBlobPublicAccess") controls whether anonymous access is allowed for blob data in a storage account. When this property is set to True, it enables public read access to blob data, which can be convenient for sharing data but may carry security risks. When set to False, it disallows public access to blob data, providing a more secure storage environment.

Rationale

If "Allow Blob Anonymous Access" is enabled, blobs can be accessed by adding the blob name to the URL to see the contents. An attacker can enumerate a blob using methods, such as brute force, and access them.

Exfiltration of data by brute force enumeration of items from a storage account may occur if this setting is set to 'Enabled'.

Impact

Additional consideration may be required for exceptional circumstances where elements of a storage account require public accessibility. In these circumstances, it is highly recommended that all data stored in the public facing storage account be reviewed for sensitive or potentially compromising data, and that sensitive or compromising data is never stored in these storage accounts.

... see more

Remediation

Open File

Remediation

From Azure Portal

1. Go to Storage Accounts.
2. For each storage account, under Settings, click Configuration.
3. Set Allow Blob Anonymous Access to Disabled.
4. Click Save.

From Powershell

For every storage account in scope, run the following:

$storageAccount = Get-AzStorageAccount -ResourceGroupName "<yourResourceGroup>" -Name "<yourStorageAccountName>" $storageAccount.AllowBlobPublicAccess = $false Set-AzStorageAccount -InputObject $storageAccount

policy.yaml

Open File

Linked Framework Sections

Section	Sub Sections	Internal Rules	Policies	Flags
💼 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);		13	13
💼 APRA CPG 234 → 💼 36e hardware and software asset controls —appropriate authorisation to prevent security compromises from unauthorised hardware and software assets;		15	15
💼 APRA CPG 234 → 💼 36f network design — to ensure authorised network traffic flows and to reduce the impact of security compromises;		28	29
💼 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.		34	36
💼 APRA CPG 234 → 💼 52d appropriate segmentation of data, based on sensitivity and access needs;		10	10
💼 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.		10	10
💼 CIS Azure v1.1.0 → 💼 3.6 Ensure that 'Public access level' is set to Private for blob containers		1	1
💼 CIS Azure v2.1.0 → 💼 3.17 Ensure that 'Allow Blob Anonymous Access' is set to 'Disabled' - Level 1 (Automated)		1	1
💼 CIS Azure v3.0.0 → 💼 4.17 Ensure that 'Allow Blob Anonymous Access' is set to 'Disabled' (Automated)			1
💼 Cloudaware Framework → 💼 Public and Anonymous Access			24
💼 FedRAMP High Security Controls → 💼 AC-3 Access Enforcement (L)(M)(H)		37	47
💼 FedRAMP High Security Controls → 💼 AC-4(21) Physical or Logical Separation of Information Flows (M)(H)		11	39
💼 FedRAMP Low Security Controls → 💼 AC-3 Access Enforcement (L)(M)(H)			47
💼 FedRAMP Moderate Security Controls → 💼 AC-3 Access Enforcement (L)(M)(H)			47
💼 FedRAMP Moderate Security Controls → 💼 AC-4(21) Physical or Logical Separation of Information Flows (M)(H)			39
💼 ISO/IEC 27001:2013 → 💼 A.9.4.1 Information access restriction		19	20
💼 NIST CSF v1.1 → 💼 PR.AC-4: Access permissions and authorizations are managed, incorporating the principles of least privilege and separation of duties		17	35
💼 NIST CSF v1.1 → 💼 PR.DS-5: Protections against data leaks are implemented		43	51
💼 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 duties			58
💼 NIST CSF v2.0 → 💼 PR.DS-01: The confidentiality, integrity, and availability of data-at-rest are protected			82
💼 NIST CSF v2.0 → 💼 PR.DS-02: The confidentiality, integrity, and availability of data-in-transit are protected			69
💼 NIST CSF v2.0 → 💼 PR.DS-10: The confidentiality, integrity, and availability of data-in-use are protected			67
💼 NIST SP 800-53 Revision 5 → 💼 AC-4(21) Information Flow Enforcement _ Physical or Logical Separation of Information Flows		35	39
💼 PCI DSS v3.2.1 → 💼 1.3 Prohibit direct public access between the Internet and any system component in the cardholder data environment.	7	9	11
💼 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.		7	8
💼 PCI DSS v3.2.1 → 💼 1.3.2 Limit inbound Internet traffic to IP addresses within the DMZ.			8
💼 PCI DSS v3.2.1 → 💼 1.3.5 Permit only “established” connections into the network.			8
💼 PCI DSS v4.0.1 → 💼 1.4.1 NSCs are implemented between trusted and untrusted networks.			10
💼 PCI DSS v4.0.1 → 💼 1.4.2 Inbound traffic from untrusted networks to trusted networks is restricted.			8
💼 PCI DSS v4.0 → 💼 1.4.1 NSCs are implemented between trusted and untrusted networks.			10
💼 PCI DSS v4.0 → 💼 1.4.2 Inbound traffic from untrusted networks to trusted networks is restricted.			8
💼 UK Cyber Essentials → 💼 1.2 Prevent access to the administrative interface from the internet		35	37