Input Validation / SQL Injection
SQL Injection (CWE-89) is a type of input validation vulnerability where the attacker submits malicious code to a web application or API through the user interface. This malicious code is then used to execute arbitrary code or modify the application's data. According to the CWE directory, SQL Injection is categorized as a Top 25 most dangerous programming errors (CWE-2022). Furthermore, the OWASP Testing Guide gives further information about this vulnerability and gives examples on how to prevent it.
SQL Injection is a dangerous vulnerability as it can lead to data leakage, data manipulation or even full system compromise. It is important to have proper input validation and to use parameterized queries in order to prevent this vulnerability.
In order to solve this vulnerability, the application should use input validation and parameterized queries. Input validation can be used to ensure that the user input is valid and does not contain malicious code. Parameterized queries should be used to ensure that the user input is not used directly in the SQL query, but is instead treated as a parameter.
The following example shows an example of an SQL Injection vulnerability.
String query = "SELECT * FROM users WHERE username = '" + userInput + "'"; Statement stmt = connection.createStatement(); ResultSet results = stmt.executeQuery(query);
In this example, the user input is not being validated and is instead directly used in the SQL query. This can lead to the user input being treated as a valid SQL statement, leading to the vulnerability.