What is SQL Injection Attack?
SQL injection is a code injection technique used to attack data-driven applications. In this attack, nefarious SQL statements are inserted into an entry field for execution. The main consequences of SQL injection attacks are loss of confidentiality and integrity of data. SQL injection attacks allow attackers to spoof identity, tamper with existing data, cause repudiation issues such as voiding transactions or changing balances. Any procedure that constructs SQL statements should be reviewed for injection vulnerabilities because SQL Server will execute all syntactically valid queries that it receives.
How to prevent a SQL Injection Attack?
The only sure way to prevent SQL Injection attacks is input validation and parametrized queries including prepared statements. The application code should never use the input directly. The developer must sanitize all input, not only web form inputs such as login forms. They must remove potential malicious code elements such as single quotes. Developers can prevent SQL Injection vulnerabilities in web applications by utilizing parameterized database queries with bound, typed parameters and careful use of parameterized stored procedures in the database. Other methods include filtering database inputs to detect and filter out malicious code from user inputs and restricting database code to prevent unintended database queries and exploration by limiting database procedures and code.
Examples of SQL Injection Attack
There are various types of injection attacks, but the most widespread and dangerous ones are SQL injection attack and XSS attack (Cross-Site Scripting). Other common forms of injection attacks include SMTP/IMAP Command Injection, Host Header injection, LDAP Injection, and CRLF Injection.