SQL Injection Tester - Security Education Tool

Learn about SQL injection vulnerabilities and how to prevent them. Educational reference for common SQL injection payloads and secure coding practices. For authorized testing only.

Educational Purpose Only - Legal Warning

This tool is for security education and authorized testing ONLY. Testing SQL injection on systems you don't own or have explicit permission to test is ILLEGAL and can result in criminal charges.

SQL Injection Payloads Reference

Common SQL injection payloads for security testing and education. Use these to test your own applications for vulnerabilities.

Classic authentication bypass

' OR '1'='1

Comment-based bypass

' OR 1=1--

Username with comment

admin'--

UNION-based injection

' UNION SELECT NULL--

AND-based injection

1' AND '1'='1

Destructive command (Bobby Tables)

'; DROP TABLE users--

Alternative bypass

' OR 'x'='x

Column enumeration

1' ORDER BY 1--

SQL Injection Prevention

• Use Prepared Statements: Parameterized queries prevent injection
• Input Validation: Validate and sanitize all user input
• Least Privilege: Database users should have minimal permissions
• Stored Procedures: Use stored procedures with proper parameterization
• ORM Frameworks: Use ORMs that handle escaping automatically
• WAF: Deploy Web Application Firewalls to detect attacks

Example: Vulnerable vs Secure Code

❌ Vulnerable (String Concatenation)

// PHP - VULNERABLE
$query = "SELECT * FROM users WHERE username = '" . $_POST['username'] . "'";

// Node.js - VULNERABLE
const query = `SELECT * FROM users WHERE username = '${username}'`;

✅ Secure (Prepared Statements)

// PHP - SECURE
$stmt = $pdo->prepare("SELECT * FROM users WHERE username = ?");
$stmt->execute([$_POST['username']]);

// Node.js - SECURE
const query = "SELECT * FROM users WHERE username = $1";
await client.query(query, [username]);

What is SQL Injection?

SQL injection (SQLi) is a web security vulnerability that allows an attacker to interfere with the queries that an application makes to its database. It occurs when user input is incorrectly filtered or not properly parameterized, allowing attackers to execute arbitrary SQL commands.

Types of SQL Injection

In-band SQLi (Classic)

Attacker uses the same channel to launch the attack and gather results. Most common and easy to exploit.

Inferential SQLi (Blind)

No data is transferred via the web application. Attacker reconstructs database structure by sending payloads and observing responses.

Out-of-band SQLi

Attacker uses different channels for attack and data retrieval (e.g., DNS or HTTP requests).

Impact of SQL Injection

Data Breach: Unauthorized access to sensitive data
Authentication Bypass: Login without valid credentials
Data Modification: Insert, update, or delete database records
Privilege Escalation: Gain administrative access
Remote Code Execution: Execute system commands on the database server
Denial of Service: Crash or overload the database

Prevention Best Practices

1. Use Prepared Statements

Parameterized queries ensure that user input is always treated as data, not executable code.

2. Input Validation

Validate all user input against expected formats, types, and ranges.

3. Least Privilege Principle

Database accounts should have minimal permissions needed for their function.

4. Use ORM Frameworks

Modern ORMs (Sequelize, TypeORM, SQLAlchemy) handle parameterization automatically.

Testing Tools

SQLMap

Automated SQL injection and database takeover tool

Burp Suite

Web application security testing platform

OWASP ZAP

Free security scanner for finding vulnerabilities

Acunetix

Commercial web vulnerability scanner

Legal and Ethical Considerations

Critical: Only test applications you own or have explicit written permission to test.

Unauthorized security testing is illegal under computer fraud and abuse laws in most jurisdictions. Violators can face criminal prosecution, fines, and imprisonment. This tool is provided strictly for educational purposes and authorized security testing.