SQL Server Security Best Practices

SQL Server is one of the most powerful and versatile database platforms available. It’s widely used in used in banking and finance, acute and behavioral health care, construction, import/export, government agencies, logistics, legal, etc. If you can think of an industry, there’s a good chance that there’s a use for SQL Server in it.

With so much data, critical data, sensitive data stored in SQL Server, keeping the data secure is a must.

In this article, we will share some SQL Server security best practices that can help you protect your data and your reputation. We will cover the following topics:

How to secure your SQL Server instance and network
How to secure your SQL Server databases and objects
How to secure your SQL Server users and roles
How to secure your SQL Server backups and audits

How to secure your SQL Server instance and network

The first step to securing your data is to secure your SQL Server instance and network. This means configuring the settings and policies that affect how SQL Server communicates with other systems and users. Here are some things to keep in mind:

Update and patch. Use the latest version of SQL Server and apply the latest patches and updates. This will ensure that you have the most recent security fixes and enhancements. If you are using a version that is out of Extended Support, upgrade as soon as possible.
Passwords. Use a strong password for the sa account and change it regularly. The sa account is the default administrator account for SQL Server and has full access to all databases and objects. You should never use the sa account for routine tasks or applications. Consider disabling or renaming the sa account.
Authentication. Use Windows Authentication instead of SQL Server Authentication whenever possible. Windows Authentication uses the credentials of the Windows user or domain account to log in to SQL Server. This provides better security and auditing than SQL Server Authentication, which uses a separate username and password stored in SQL Server.
Access. Disable or limit remote access to SQL Server. Remote access allows users or applications to connect to SQL Server from another computer or network. This can broaden the attack vector and expose your SQL Server to potential attacks or unauthorized access. Disable remote access if you don’t need it. Limit access to specific IP addresses or ports if you do.
Encryption. Enable encryption for data in transit and at rest. Encryption protects your data from being read or modified by unauthorized parties. You can use SSL/TLS to encrypt the data in transit between SQL Server and the client application. You can also use Transparent Data Encryption (TDE) to encrypt the data at rest on the disk.
Surface area. Reduce the number of potential areas for attack by uninstalling or disabling unused SQL Server components.

How to secure your SQL Server databases and objects

The next step to securing your SQL Server is to secure your SQL Server databases and objects. This means controlling the access and permissions to the data and objects stored in SQL Server. Here are a few tips:

Least privilege. Use the principle of least privilege. This means granting only the minimum level of permissions required for a user or role to perform their tasks. This reduces the risk of unauthorized or accidental changes or damage to your data or objects.
Schemas. Use schemas to organize and isolate your objects. Schemas are logical containers that group related objects such as tables, views, stored procedures, etc. You can use schemas to separate different types of objects or different business domains. You can also use schemas to assign permissions more easily and efficiently.
Encryption. Use encryption for sensitive data. Encryption protects your data from being read or modified by unauthorized parties. You can use column-level encryption or Always Encrypted to encrypt specific columns of data in your tables. You can also use row-level security or dynamic data masking to restrict or obfuscate the data returned by queries based on user roles or conditions.

How to secure your SQL Server users and roles

The third step to securing your SQL Server is to secure your SQL Server users and roles. This means managing the identities and privileges of the users who access SQL Server. Here are some tips to secure the users and roles:

Users. Create separate user accounts for different purposes and applications. You should avoid using generic or shared user accounts that have broad or unclear responsibilities. You should also avoid using service accounts that run background processes or services for logging in interactively.
Roles. Use roles to group users with similar permissions. Roles are collections of permissions that can be granted or revoked as a unit. You can use roles to simplify the management of permissions and reduce the number of individual grants or revokes.
Auditing. Use auditing to track user activity and changes. Auditing can record who did what, when, where, and how on your SQL Server instance. You can use auditing to monitor user behavior, detect anomalies, troubleshoot issues, enforce policies, and comply with regulations.

How to secure your SQL Server backups and audits

The final step to securing your SQL Server is to secure your SQL Server backups and audits. This means protecting the copies of your data and logs that are stored outside of SQL Server. Here are some ways to secure your SQL Server backups and audits:

Backup encryption. Use backup encryption to protect your backup files. Backup encryption encrypts the data in your backup files so that only authorized parties can restore them. You can use backup encryption with any recovery model and any backup type. You can also use compression to reduce the size of your backup files.
Backup verification. Use backup verification to ensure the integrity of your backup files. Backup verification checks the consistency and validity of your backup files and reports any errors or warnings.
Audit encryption. Use audit encryption to protect your SQL Audit files. Audit encryption encrypts the data in your audit files so that only authorized parties can read them. You can use audit encryption with any audit destination and any audit action group. You can also use compression to reduce the size of your audit files.
Audit retention. Use audit retention to manage the storage and deletion of your audit files. Audit retention specifies how long you want to keep your audit files and when you want to delete them. You can use audit retention to comply with regulatory or business requirements and to optimize disk space usage.

Conclusion

SQL Server security is a vital aspect of managing your data and protecting your business. By following these SQL Server security best practices, you can take the steps necessary to harden your SQL Servers from unauthorized access, malicious attacks, and data breaches. For more information, check out SQL Server security best practices – SQL Server | Microsoft Learn. Also see:

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