Are there best practices for securing external files and preventing injection when using parameters in PHP?

When using parameters in PHP to interact with external files, it is crucial to sanitize and validate user input to prevent injection attacks. Best practices include using prepared statements for database queries, validating file paths, and using functions like realpath() to ensure the file path is safe. Additionally, restricting file permissions and using secure file upload methods can further enhance security. 

// Example of securing external files and preventing injection in PHP

// Sanitize and validate user input for file path
$file_path = realpath($_GET['file']);
if ($file_path === false || strpos($file_path, '/path/to/allowed/directory/') !== 0) {
    die('Invalid file path');
}

// Use file_get_contents() to safely read the file
$file_contents = file_get_contents($file_path);

Keywords

PHP security external files injection prevention parameterized queries

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