Why SSRS reports should only have readonly access

Introduction

Security is paramount when it comes to database operations. Microsoft SQL Server Reporting Services (SSRS) is a powerful tool for generating dynamic reports from SQL Server databases. But with its vast capabilities, it's crucial to implement it securely.

One often overlooked security measure is limiting SSRS reports to readonly access to the database. This article dives into the reasons behind this and the dangers of enabling stored procedures with more than just read capabilities.

The Risks of Unrestricted Access

At first glance, it might seem convenient to grant SSRS reports full access to a database. However, this approach presents numerous potential security issues.

• Data Manipulation: A report with write access can unintentionally modify data, which might lead to data inconsistencies.
• Data Leakage: If an unauthorized person gains access to an SSRS report, they might be able to extract confidential data.
• Increased Vulnerability: Granting more permissions than necessary increases the surface area for potential attacks.

Stored Procedures: Not Just for Reading

Stored procedures are widely used in SQL Server because of their efficiency and modularity. But when used with SSRS, caution is advised.

EXEC report.sales_orders_today;

Consider the above stored procedure. If it's meant for reading data, it's fine. But what if it has capabilities beyond that?

With a stored procedure you could basically do whatever data manipulations you would like.

EXEC shipping.mark_for_loading @id = 'XXX';

The stored procedure above is letting a user mark a shipment for loading. With this possible from SSRS you wouldn't even need to start your warehouse application. You could build your own application from SSRS. Isn't it great? 😍

But WAIT a minute... is this really safe? 😱

Potential Dangers of Unrestricted Stored Procedures

Think again, if SSRS is granted access to manipulating data, a malicious user could easily go havoc on you database.

• Data Deletion: A stored procedure with delete capabilities might accidentally remove valuable data.
• Unauthorized Changes: A malicious user can use the stored procedure to introduce unauthorized changes.
• System Exploits: Some stored procedures can execute system-level commands, which might be exploited by attackers.

Setting Up Schemas and Logins for SSRS Security

As you venture deeper into the world of SQL Server Reporting Services (SSRS), understanding how to securely set up schemas and logins becomes paramount. These components play pivotal roles in determining how data can be accessed and manipulated.

Here are some best practices to ensure your SSRS configurations are both functional and secure:

1. Schema Segregation

Organizing database objects into distinct schemas based on their roles and access levels helps in achieving clarity and granularity in permissions.

• Data Schemas: Contain tables, views, and other objects housing your data.
• Report Schemas: Dedicated exclusively for SSRS, these schemas contain objects like stored procedures or views tailored for reporting purposes.

2. Principle of Least Privilege (PoLP)

Always assign the minimum necessary permissions to any login or role. For SSRS, a readonly role for the database is should be sufficient. Otherwise you should reevaluate how you use your reports.

3. Dedicated SSRS Service Account

Create a dedicated SQL Server login for the SSRS service. This account should:

• Only have permissions to the Report Schemas.
• Not be a member of the db_owner role.
• Be regularly audited for unusual activity.

4. Strong Password Policies

For SQL Server logins, enforce a strong password policy. This includes:

• Regular password rotation.
• Using complex passwords with a mix of characters, numbers, and symbols.
• Disallowing common or previously breached passwords.

5. Auditing and Monitoring

Implement regular audits on your SSRS configurations. This helps in:

• Identifying any misconfigurations or excessive permissions.
• Detecting suspicious activities, like multiple failed login attempts.
• Ensuring compliance with industry regulations.

6. Avoid using SA Account

Never use the System Administrator (SA) account for SSRS. The SA account has unrestricted access, making it a prime target for attackers. Instead, use the dedicated SSRS service account mentioned earlier.

Conclusion

While SSRS offers vast capabilities for dynamic reporting, it's crucial to employ best security practices. Limiting SSRS reports to readonly access and ensuring stored procedures only read from tables significantly reduces the chances of security breaches and data leakages. Always follow the principle of least privilege: grant only the minimum required permissions.

Stay Informed, Stay Secure

Database security is an ever-evolving field. By understanding potential vulnerabilities and mitigating them proactively, you safeguard your data assets. Always be on the lookout for new developments and best practices.