validate data on unused API endpoint

api/index.php

@@ -1,10 +1,17 @@
 <?php
 reset($_GET);
 $function = (key($_GET) ? str_replace("/", "_", key($_GET)) : false);
+function validateData($data)
+{
+	$data = trim($data);
+	$data = stripslashes($data);
+	return htmlspecialchars($data);
+}
+
 switch ($function) {
 	case 'v1_auth':
 		$group = ($_GET['group']) ?? 0;
-		header('Location: v2/auth?group=' . $group);
+		header('Location: v2/auth?group=' . validateData($group));
 		exit;
 	default:
 		// Forward everything to v2 api
@@ -12,4 +19,4 @@ switch ($function) {
 		$result['statusText'] = "Please Use api/v2";
 		break;
 }
-header('Location: v2/');
+header('Location: v2/');