3.13 Ensure Storage logging is Enabled for Blob Service for 'Read', 'Write', and 'Delete' requests

Information

The Storage Blob service provides scalable, cost-efficient object storage in the cloud. Storage Logging happens server-side and allows details for both successful and failed requests to be recorded in the storage account. These logs allow users to see the details of read, write, and delete operations against the blobs. Storage Logging log entries contain the following information about individual requests: timing information such as start time, end-to-end latency, and server latency; authentication details; concurrency information; and the sizes of the request and response messages.

Rationale:

Storage Analytics logs contain detailed information about successful and failed requests to a storage service. This information can be used to monitor each individual request to a storage service for increased security or diagnostics. Requests are logged on a best-effort basis.

Storage Analytics logging is not enabled by default for your storage account.

Impact:

Being a level 2, enabling this setting can have a high impact on the cost of data storage used for logging more data per each request. Do not enable this without determining your need for this level of logging or forget to check in on data usage and projected cost.

Solution

From Azure Portal

From the default portal page select Storage Accounts.

Select the specific Storage Account.

Click the Diagnostics settings under the Monitoring section in the left column.

Select the 'blob' tab indented below the storage account.

Click '+ Add diagnostic setting'.

Select StorageRead, StorageWrite and StorageDelete options under the Logging section to enable Storage Logging for Blob service.

Select a destination for your logs to be sent to.

From Azure CLI
Use the below command to enable the Storage Logging for Blob service.

az storage logging update --account-name <storageAccountName> --account-key <storageAccountKey> --services b --log rwd --retention 90

Default Value:

By default, storage account blob service logging is disabled for read, write, and delete operations.

See Also

https://workbench.cisecurity.org/benchmarks/10624