What is SQL Injection (SQLi)?
SQL injection is a web security vulnerability where attackers use a code injection technique to interfere with a business’s database. They inject malicious SQL commands into the system which lets them access confidential and sensitive business data.
This cyber threat usually occurs when entry fields open for user inputs allow SQL commands to enter the database unintentionally. Hackers use injection attacks like SQL to perform multiple activities within a user’s server such as:
- Access and retrieve sensitive business data
- Delete or modify existing information from the database
- Execute changes across the data that impact the application’s behavior
There are three prominent types of SQL injections that businesses must know about.
- In-band SQL Injection (Classic SQLi)
- Inferential SQL Injection (Blind SQLi)
- Out-of-Band SQL Injection
Arguably the most common SQL injection attack is In-band SQLi. In this, the attacker uses the same communication channel to send malicious SQL queries and gather results.
In Inferential SQLi, the attacker doesn’t receive data directly as in In-band SQLi. Instead, they reconstruct the database structure by sending payloads and observing responses.
In Out-of-Band SQLi, the attacker uses a different communication channel to attack and a different one to gather results. This SQLi type is quite slow and hence is very uncommon.
Major Consequences of a SQL Injection Attack
A successfully executed SQL injection attack can have significant consequences that may negatively impact a business. Some of these consequences you should know about are:
- Confidentiality Breach
- Data Integration
- Authentication Challenges
SQL injection attacks compromise the confidentiality of sensitive data such as usernames and passwords, credit card details, etc., stored in databases.
Once a hacker goes through with an SQL injection attack and has access to the company’s sensitive data, the overall integrity is compromised.
Businesses that use weak SQL commands to check usernames and passwords may allow attackers to access the database without having prior credentials.
SQL Injection Attack Prevention Measures to Follow
Preventing SQL injections from attacking your system demands proactive mitigation practices, and incorporating effective security measures such as:
- Filtering Database Inputs
- Restricting Database Code
- Implement the Principle of Least Privilege
- Use Parameterized Statements (Prepared Statements)
- Leverage Web Application Firewalls (WAF)
The first and most important step to prevent SQL injection attacks is to carefully evaluate inputs entering the database to filter out malicious code. Following this practice from the beginning keeps illegitimate user inputs from entering your system.
Although filtering inputs is crucial, it’s barely the best solution to prevent SQLi attacks. This is why you must also restrict the code available to your database to reduce the risk of attackers sending unethical SQL injection commands and exploiting data vulnerabilities.
Another SQL injection attack prevention measure to follow is enforcing the principle of least privilege. According to this principle, a user only gets access to the data or resources required for a particular task. This minimizes the risk of attacks like security breaches.
Using parameterized statements is also a great way to mitigate the risk of SQLi attacks. A parameterized statement or query is a technique that separates a SQL query from user inputs. This eventually prevents an attacker from executing malicious codes.
A web application firewall can filter and monitor incoming HTTP traffic from the internet to a web application. This will help you detect and block SQL injection attempts and other malicious practices keeping your database secured from various cyber vulnerabilities.