What security considerations should be taken into account when outputting images in PHP based on database queries?

When outputting images in PHP based on database queries, it is important to validate user input to prevent SQL injection attacks. Additionally, it is crucial to sanitize the image data to prevent cross-site scripting attacks. Finally, ensure that the image files are stored securely and access to them is restricted to authorized users only. 

// Example code snippet for outputting images securely in PHP based on database queries

// Validate and sanitize user input
$image_id = isset($_GET['image_id']) ? intval($_GET['image_id']) : 0;

// Query the database to retrieve the image data
$stmt = $pdo->prepare("SELECT image_data FROM images WHERE image_id = :image_id");
$stmt->bindParam(':image_id', $image_id, PDO::PARAM_INT);
$stmt->execute();
$image_data = $stmt->fetchColumn();

// Output the image with proper headers
header("Content-type: image/jpeg");
echo $image_data;

Keywords

SQL injection image processing content security policy data validation cross-site scripting

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