SQL Injection (SQLi) is a web security vulnerability that allows attackers to interfere with queries an application makes to its database. Below are four major aspects of practical exploitation:
- Authentication Bypass
Attackers manipulate input fields (such as login forms) to bypass authentication mechanisms. By injecting crafted SQL statements, they can log in without valid credentials.
Impact: Unauthorized access to user or administrator accounts.
- Data Extraction
Once a vulnerability is confirmed, attackers can retrieve sensitive information from the database, such as usernames, passwords, emails, and financial records. Common techniques include UNION-based, error-based, and blind SQL injection.
Impact: Data breaches and exposure of confidential information.
- Database Enumeration
Attackers gather structural information about the database, including table names, column names, database version, and schema details. This information helps in planning further attacks.
Impact: Increased effectiveness of deeper exploitation.
- Remote Code Execution (Advanced Cases)
In poorly configured systems, SQL Injection can lead to writing files on the server or executing system-level commands through database features.
Impact: Full server compromise and complete system takeover.