wGrow - Team Notes

It's essential to ensure that SQL Server is secure and protected against potential cyber threats. Government cybersecurity requirements mandate that all agencies' SQL Server must undergo hardening before being put into production. We summarize the comprehensive SQL Server hardening checklist and best practices to secure SQL Server environment for an agency data centre. 

1. Keep the SQL Server and Windows Server Up-to-Date

One of the first steps in securing SQL Server is to ensure that both the SQL Server and Windows Server are up-to-date with the latest security patches and hotfixes. Keeping systems updated will help protect against known vulnerabilities and potential security threats.

2. Use Windows Authentication

It's recommended to use Windows Authentication instead of SQL Authentication to access the SQL Server. Using Windows Authentication provides an additional layer of security and helps enforce the principle of least privilege.

3. Strong Password Policy

Implement a strong password policy for SQL Server logins and enforce regular password changes. A strong password policy should include a minimum length requirement, complexity requirements, and a history of previous passwords to prevent re-use.

4. Limit Sysadmin Privileges

Limit the number of SQL Server logins with sysadmin privileges to the minimum number required. This will help reduce the risk of unauthorized access and potential security breaches.

5. Grant Minimum Permissions

Adhere to the principle of least privilege and grant the minimum permissions necessary for users to perform their jobs. This will reduce the risk of unauthorized access to sensitive data and improve the overall security of the SQL Server environment.

6. Enable SQL Server Audit

Enable the SQL Server audit feature to track and log any security-related events. This will help you monitor and detect any potential security threats and improve overall security posture.

7. Encrypt Data Transmission and Storage

Encrypting data transmission and storage is critical to protecting sensitive data. Use SSL/TLS encryption for data transmission and TDE (Transparent Data Encryption) for data storage to ensure that data is protected.

8. Enable SQL Server Firewall

The SQL Server firewall should be enabled and configured to limit incoming traffic to only those IP addresses that need access to the SQL Server. This will help reduce the risk of unauthorized access and potential security breaches.

9. Monitor Error Logs and Event Logs

Monitor the SQL Server error log and the Windows event logs for any security-related events. This will help you detect and respond to any potential security threats in a timely manner.

10. Use Network Segmentation

Use a network segmentation strategy to separate the SQL Server from other systems and limit access to the SQL Server only to necessary systems. This will reduce the risk of unauthorized access and improve the overall security of the SQL Server environment.

11. Check Linked Servers

Check the linked servers to make sure that they are secure and properly configured. Consider disabling or removing any unnecessary linked servers to reduce the risk of potential security breaches.

12. Isolate from the Internet

Verify that the SQL Server is isolated from the internet and is not directly accessible from the internet. This will reduce the risk of unauthorized access and potential security breaches.

Scripts to Implement SQL Server Hardening Best Practices

Here are some sample scripts that you can use to implement some of the best practices discussed above:

-- Enable SQL Server Audit
USE [master]
GO
CREATE SERVER AUDIT [Audit_Server_Access]
TO FILE
(   FILEPATH = 'C:\Audit'
,MAXSIZE = 100 MB
,MAX_ROLLOVER_FILES = 2147483647
,RESERVE_DISK_SPACE = OFF
)
WITH
( QUEUE_DELAY = 1000
,ON_FAILURE = CONTINUE
)
GO

-- Enable Auditing for Login and Logout events
USE [master]
GO
CREATE SERVER AUDIT SPECIFICATION [Audit_Login_Logout]
FOR SERVER AUDIT [Audit_Server_Access]
ADD (FAILED_LOGIN_GROUP), ADD (SUCCESSFUL_LOGIN_GROUP)
WITH (STATE = ON)
GO

-- Enable Transparent Data Encryption
USE [master]
GO
CREATE MASTER KEY ENCRYPTION BY PASSWORD = 'Your_Strong_Password_Here!';
GO
CREATE CERTIFICATE TDECert WITH SUBJECT = 'TDE Certificate';
GO
USE [Your_Database_Name]
GO
CREATE DATABASE ENCRYPTION KEY
WITH ALGORITHM = AES_256
ENCRYPTION BY SERVER CERTIFICATE TDECert;
GO
ALTER DATABASE [Your_Database_Name] SET ENCRYPTION ON;
GO

-- Check linked servers
USE [master]
GO
EXEC sp_linkedservers
GO

-- Disable or remove unnecessary linked servers
USE [master]
GO
EXEC sp_dropserver 'LinkedServerName', 'droplogins';
GO

Conclusion

In this article, we have summarized a comprehensive SQL Server hardening checklist and best practices to secure SQL Server environment. Implementing these best practices and regularly reviewing and updating them will help protect SQL Server against potential cyber threats and improve overall security posture. Additionally, the sample scripts provided can be used as a starting point for implementing some of these best practices.