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.cyberstrike/skill/CIS_benchmarks/Cloud_Providers/Microsoft_Azure/cis-microsoft-azure-storage-services/cis-azure-storage-11.1/SKILL.md). Install upstream withnpx skills add CyberStrikeus/CyberStrike --skill cis-azure-storage-11.1. Copyright stays with the author.
11.1 Ensure 'Allowed Protocols' for shared access signature (SAS) tokens is set to 'HTTPS Only' (Manual)
Description
Shared access signatures (SAS) can be used to grant limited access to Azure Storage resources. When generating a SAS, it is possible to specify the allowed protocols for a request made with the SAS. It is recommended to allow requests over HTTPS only.
Rationale
If a SAS is passed over HTTP and intercepted, an attacker performing a man-in-the-middle attack can read the SAS. Then, they can use that SAS just as the intended user could have. This can potentially compromise sensitive data or allow for data corruption by the malicious user.
Impact
SAS can pose security risks if they are not managed carefully.
Audit Procedure
It is not possible to audit generated SAS.
Expected Result
All SAS tokens are generated with Allowed protocols set to HTTPS only.
Remediation
Remediate from Azure Portal
If SAS have been created to allow HTTP and were created with a stored access policy (SAP), the SAS can be revoked by deleting the SAP or updating the SAP expiration time to a time in the past:
- Go to
Storage accounts. - Click on a storage account.
- Under
Data storage, clickContainers. - Click the three dots next to a container.
- Click
Access policy. - Click the three dots next to an access policy.
- Click
Delete. - Click
Save. - Repeat steps 1-8 as needed to revoke SAS created with SAP.
If SAS have been created to allow HTTP and were not created with a SAP, the SAS can be revoked by regenerating the storage account access keys:
Note: Regenerating access keys can affect any applications or Azure services that are dependent on the storage account key.
- Go to
Storage accounts. - Click on a storage account.
- Under
Security + networking, clickAccess keys. - Next to each key, click
Rotate key. - Click
Yesto confirm. - Repeat steps 1-5 as needed to revoke SAS.
Default Value
When generating a SAS, the default selection for Allowed protocols is HTTPS only.
References
- https://learn.microsoft.com/en-us/azure/storage/common/storage-sas-overview
- https://learn.microsoft.com/en-us/azure/storage/common/storage-account-keys-manage
Additional Information
This recommendation is based on the recommendation Ensure 'Allowed Protocols' for shared access signature (SAS) tokens is set to 'HTTPS Only', from the Common Reference Recommendations > Secrets and Keys > Shared Access Signatures section.
Profile
Level 1 | Manual