SQL injection is a type of web application security vulnerability that allows an attacker to inject malicious SQL code into a web application’s database in order to extract or modify sensitive data. This is typically done by inserting malicious input into a web form or URL, which is then processed by the application’s database.
When a web application uses user-input data to construct SQL queries, an attacker can inject malicious SQL code as part of the input. If the application does not properly sanitize or validate the input, the malicious code can be executed by the database, allowing the attacker to access or modify sensitive data.
SQL injection attacks can be used to extract sensitive data, such as passwords or credit card numbers, or to modify data, such as inserting or deleting records. In some cases, an attacker may even be able to gain administrative access to the database or entire system.
SQL injection attacks can be prevented by using prepared statements, input validation, and escaping special characters to ensure that user-input data is not executed as SQL code. Regular security testing and code reviews can also help identify and fix vulnerabilities before they can be exploited.