Why Do Threat Actors Opt for SQL Injections?
SQL’s biggest benefit — greater ease in accessing and manipulating databases — is also what makes it vulnerable to malicious misuse. Without SQL’s gift for entering databases simply and swiftly, SQL injection attacks wouldn’t pose as much of a threat.
Easily exploited by threat actors, SQL injections are limited not by the size or complexity of the victims’ databases but by the skill and imagination of the perpetrators, according to the Open Worldwide Application Security Project.
SQL injection attacks take several forms, including:
- In-band SQL injection: This is the simplest and most common type of SQL injection attack, using the input fields of a website, search bar or URL. Because the channel can be accessed by both the victim and the threat actor, this type of attack is often the most straightforward to fix.
- Out-of-band SQL injection: This is when a threat actor uses a different channel to gain results than it used to execute the attack. After a malicious user injects SQL code into the good code, the output is funneled through an external location that is not under the victim’s control. This type of attack is harder to execute, but highly effective.
- Blind SQL injection: In a blind attack, malicious users leverage an error page to gain information about how a server operates, according to IBM. The database is not immediately accessed directly, but threat actors learn enough about a system to work out what they want to know. Blind SQL injections are also known as inferential SQL injections, because information is gained by inference.
A classic example of a SQL injection attack code involves manipulating username and password fields. Good-faith users of a web form that uses SQL statements would enter their actual username and password to gain legitimate entry. Malicious users can manipulate this entry point by providing a string of data that falsely registers as legitimate. If one part of the SQL data string is registered as legitimate, the entire statement is read as valid.
Say a registered user goes by username “janedoe” and uses the password “abcd123.” In s SQL statement-based portal, an attacker could provide a different entry that the system would recognize as valid — for example, username “1=1,” which the system would incorrectly read as “true” (because 1 does equal 1) and thus as valid.
Security Breaches That Stem from a SQL Injection Attack
Once a SQL injection attack is successful, organizational data falls into that user’s hands. Immediate security risks include data theft, data manipulation, privacy violations and regulatory breaches, and queries designed to overwhelm a server to the point where operations slow or halt.
From there, the risk spreads. A SQL injection attack can lead to reputational damage and legal remediation which can quickly become an ongoing and expensive endeavor.
In the case of MOVEit Transfer, the Cl0p ransomware group targeted an organization known for transferring files containing sensitive data. Threat actors performed a SQL injection that allowed them to upload a web shell onto the company’s server, which then allowed them to manipulate server files and user accounts.
In addition to the resource costs of fixing the vulnerability and tending to its clients, the company is now facing five class action lawsuits brought by victims whose data became exposed as a result of the SQL injection.
How to Prevent SQL Injection Attacks
Programmers can apply various defenses against injection attacks. Among them: altering the back-end query (specifically by reconsidering the use of concatenation) or limiting user-supplied input to avoid bad-faith language. Here are a few examples:
- Use parameterized queries in prepared statements. Separating user input from queries prevents it from being injected into SQL statements. By using placeholders for parameters within a prepared statement, even if a malicious user inputs a SQL command, it won’t penetrate the system.
- Use stored procedures. Using a stored procedure forces developers to build SQL statements that are automatically parameterized. Unlike a parameterized query that comes as part of a prepared statement, a stored procedure is stored in the database itself.
- Use input validation. Set up user input fields to accept only certain types of input. For example, if a user field is expected to be all alphabetic characters, creating a user input field that will accept only letters, preventing malicious users from injecting SQL code.
- Lean on the principle of least privilege. On an administrative level, adjusting permissions so that only valid users have access to certain data and resources can serve as a defensive measure against SQL injection attacks.
With these defensive strategies in mind, businesses can protect their systems against SQL injection attacks while maintaining a user-friendly entry point.