What are the potential risks of not properly validating user input, such as IDs, in PHP applications?

Not properly validating user input, such as IDs, in PHP applications can lead to security vulnerabilities like SQL injection and cross-site scripting attacks. To mitigate these risks, it is crucial to sanitize and validate user input before using it in database queries or displaying it on the webpage. 

// Example of validating and sanitizing user input for an ID parameter
$id = isset($_GET['id']) ? $_GET['id'] : null;
if (!is_numeric($id)) {
    // Invalid input, handle error
    die("Invalid ID");
}

// Sanitize the ID to prevent SQL injection
$id = intval($id);

// Use the sanitized ID in your database query or other operations

Keywords

SQL injection Cross-site scripting (XSS) Data validation Input sanitization Security vulnerabilities

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