Tag Archives: security

How to Secure Your Azure SQL Database

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  1. Authentication and Authorization:
    • Use Azure Active Directory (Azure AD) authentication for better security.
    • Implement firewall rules to control access to your database.
    • Assign minimal permissions to users based on their roles (principle of least privilege).
  2. Encryption:
    • Enable Transparent Data Encryption (TDE) to protect data at rest.
    • Use Always Encrypted to secure sensitive data in transit.
    • Consider client-side encryption for additional protection.
  3. Auditing and Monitoring:
    • Enable Azure SQL Auditing to track database activity.
    • Set up Azure Monitor to receive alerts and insights.
    • Regularly review logs and audit trails.
  4. Network Security:
    • Isolate your database using Virtual Network Service Endpoints.
    • Restrict public access and use private endpoints.
  5. Patch Management:
    • Keep your database engine up to date with the latest security patches.
    • Regularly review vulnerability assessments.
  6. Backup and Recovery:
    • Implement automated backups and test recovery procedures (remember a backup is only theoretically there unless it has been tested and proven to work).
    • Store backups conforming to the 3-2-1 Backup Rule explained below (do not assume your backups are safe just because they are in the cloud).

The 3-2-1 Backup Rule: Ensuring Data Resilience

The 3-2-1 Rule is a robust strategy that emphasizes redundancy, resilience, and data availability. Here’s what it entails:

  1. Three Copies of Your Data:
    • Maintain the original data and create at least two additional copies.
  2. Two Different Types of Media for Storage:
    • Store your data on distinct forms of media (e.g., hard drives, tapes) to enhance redundancy.
  3. At Least One Copy Off-Site:
    • Safeguard one backup copy in an off-site location, separate from your primary data and on-site backups.

By adhering to this rule, you mitigate single points of failure, protect against corruption, and ensure data safety even in unexpected events or disasters

How to enable and disable xp_cmdshell

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xp_cmdshell is an extended stored procedure provided by Microsoft and stored in the master database. This procedure allows you to issue operating system commands directly to the Windows command shell via T-SQL code.

By default, the xp_cmdshell option is disabled on new installations. Along with other unwanted behavior malicious users can elevate their privileges with the use of xp_cmdshell. For this reason it is generally recommend to leave xp_cmdshell disabled. It can be enabled by using the Policy-Based Management or by running the sp_configure system stored procedure as shown in the following code example:

Use Master
GO

EXEC master.dbo.sp_configure 'show advanced options', 1
RECONFIGURE WITH OVERRIDE
GO

EXEC master.dbo.sp_configure 'xp_cmdshell', 1
RECONFIGURE WITH OVERRIDE
GO

 

To disable xp_cmdshell use the following code example. Note: The following example also sets show advanced options server configuration option to 0. It is best practice to leave this option in the default state of 0 to stop the enabling of features.

Use Master
GO

EXEC master.dbo.sp_configure 'xp_cmdshell', 0
RECONFIGURE WITH OVERRIDE
GO

EXEC master.dbo.sp_configure 'show advanced options', 0
RECONFIGURE WITH OVERRIDE
GO