It’s 2024 – and SQL Injection is still a thing. It’s hard to believe that people aren’t aware of the possibility of a SQL injection attack in the current environment, but here’s a thought – it’s going to get worse. Why do I say that? Because instead of having a sensible developer with 30 years of dealing with idiots attacking their code and trying to make it do things it’s not meant to, you are going to have code going into production written by AI responding to a prompt like “Hey CHAT GTP – how do I write a form that people can send me comments about their order through?”. **SIGH** Let’s take a step back.

Imagine leaving your front door wide open, with a sign saying, “Welcome, come in!” That’s what a poorly secured SQL Server feels like to a malicious actor exploiting SQL injection vulnerabilities. SQL injection is a technique where attackers inject malicious SQL code into input fields, tricking the database into executing commands it shouldn’t. It’s one of the most common and devastating attack methods, and as a SQL Server DBA, it’s your job to ensure the door stays locked.

SQL injection doesn’t discriminate—it targets any system that relies on improperly sanitized user inputs. Picture a login form that asks for a username and password. If the application inserts these inputs directly into a SQL query without validation, an attacker could manipulate the input to bypass authentication, exfiltrate data, or even gain administrative control. For example, entering ' OR 1=1 -- as a password might turn the SQL statement into something always true, effectively allowing the attacker in without knowing any credentials.

As I mentioned above, we are going to get an increase in the number of inexperienced people putting code into the world. We simply can’t rely on the frontend being secure. It may be…and that would be great, but if our SQL Server is being breached because someone wrote a poor app it’s as much the DBA’s fault for not closing the door as it is the developers for opening it.

Defending against SQL injection requires more than locking down your SQL Server—it’s about creating multiple layers of defense, much like securing a fortress. The first line of defense is always input validation and parameterized queries. Instead of allowing raw input to dictate how your queries are constructed, parameterized queries use placeholders for inputs, ensuring the database treats them as data rather than executable code. Think of it as giving someone a safe deposit box key that only works for one specific box, rather than granting them access to the entire vault. We can look for that as DBA’s, and we can talk to our developers about the queries that they are writing.

Moving on from a parameterized query we can enforce input via stored procedures and now the code sits in the DBA realm. By encapsulating SQL code in a controlled environment, you reduce the risk of input tampering. However, don’t fall into the trap of thinking all stored procedures are inherently safe. If you dynamically construct SQL strings within a stored procedure, the risk of injection remains. And you want to know when stored procedures are failing. If you write it in such a way that it cannot fail so long as the input is valid – when it fails what does that tell you?

Another crucial defense mechanism is principle of least privilege. Every application user doesn’t need administrative access to the database. Instead, grant permissions based on necessity. If a user only needs to read data, don’t let them modify it. This limits the potential damage of a successful SQL injection attack. What’s more, SQL Server has a wonderful feature called roles that everybody uses like this: Do you need read access – I’ll give you db-reader, do you need write access – I’ll give you db_writer, oh you need both – I’ll give you db_owner. It’s crazy. SQL Server access is so much more granular than that. It you are exposing your database to a web app – what access does that app actually need? Oh it only writes to one table? So give it access to just that table. I know it’s more work and fiddlier – but it protects your data. So do it.

Encryption also plays a role. While it won’t stop an injection attack, encrypting sensitive data—like passwords—adds another barrier. Even if attackers gain access, encrypted data is far less useful without the decryption key.

Finally, don’t underestimate the power of monitoring and auditing. Tools like SQL Server Audit can track login attempts and query execution, providing early warning signs of unusual activity. Regular penetration testing is also invaluable; it’s like hiring a locksmith to find weaknesses in your security setup before a burglar does.

SQL injection is a persistent threat, and it’s probably going to get worse rather than better, but it’s not an inevitable one. By treating your SQL Server like a fortress and layering your defenses, you can ensure that even the most determined attacker finds nothing but locked doors. After all, security isn’t just about keeping bad actors out; it’s about building trust with those who rely on you to safeguard their data. And in this case, trust is the most valuable currency of all.