As a SQL Server database administrator (DBA), one of the top concerns is ensuring the security of your SQL Server environment. One common vulnerability is weak passwords that can be easily exploited by hackers. In this blog post, we will discuss how to find weak passwords in SQL Server and provide recommendations for improving security.

Using Windows Authentication

One of the best practices for securing SQL Server is to use Windows Authentication whenever possible. By using Windows Authentication, you can leverage the security features provided by the operating system, such as strong password policies and Active Directory integration. This significantly reduces the risk of unauthorized access to your SQL Server.

Enforcing Password Policy

If you decide to use SQL Authentication, it is crucial to enforce a strong password policy. SQL Server provides a setting called “Enforce Password Policy” that ensures users choose a strong password. By enabling this setting, you can enforce password complexity requirements, such as minimum length, use of uppercase and lowercase letters, numbers, and special characters.

Using PWDCOMPARE Function

SQL Server offers a built-in function called PWDCOMPARE, which can be useful in finding known weak passwords. This function compares a password with its hash value stored in the system catalog. Here is an example query that demonstrates the usage of PWDCOMPARE:

SELECT NAME, NAME AS 'password'
FROM sys.sql_logins
WHERE Pwdcompare(NAME, password_hash) = 1
UNION
SELECT NAME, '' AS 'password'
FROM sys.sql_logins
WHERE Pwdcompare('', password_hash) = 1
UNION
SELECT NAME, 'password123' AS 'password'
FROM sys.sql_logins
WHERE Pwdcompare('password123', password_hash) = 1

In the above query, we are searching for three types of weak passwords:

1. Password same as the username
2. Blank password
3. Password = “password123”

These are some of the most common weak passwords used in the industry. You can extend this query by modifying it and adding more weak passwords to suit your specific needs.

By running this query, you can identify any SQL logins with weak passwords and take appropriate action to strengthen them.

Conclusion

Securing SQL Server is a critical task for DBAs. By following best practices such as using Windows Authentication and enforcing strong password policies, you can significantly reduce the risk of unauthorized access to your SQL Server environment. Additionally, utilizing the PWDCOMPARE function can help you identify and address weak passwords in your system.

Have you ever encountered the need to find weak passwords in your SQL Server environment? Share your experiences and thoughts in the comments below!