fixing minor security issues

app-code/api/manage/fetch_users.php

@@ -16,21 +16,32 @@ if ($conn->connect_error) {
 }
 
 $search = trim($_GET['search'] ?? '');
-$sort = $_GET['sort'] ?? 'id';
+$sort = $_GET['sort'] ?? '';
 $order = strtoupper($_GET['order'] ?? 'ASC') === 'DESC' ? 'DESC' : 'ASC';
 
-$allowedSorts = ['id', 'username'];
-if (!in_array($sort, $allowedSorts)) {
-    $sort = 'id';
-}
-
 if ($search !== '') {
-    $query = "SELECT id, username FROM users WHERE username LIKE ? ORDER BY $sort $order";
+    if ($sort === 'username') {
+        $query = $order === 'DESC'
+            ? "SELECT id, username FROM users WHERE username LIKE ? ORDER BY username DESC"
+            : "SELECT id, username FROM users WHERE username LIKE ? ORDER BY username ASC";
+    } else {
+        $query = $order === 'DESC'
+            ? "SELECT id, username FROM users WHERE username LIKE ? ORDER BY id DESC"
+            : "SELECT id, username FROM users WHERE username LIKE ? ORDER BY id ASC";
+    }
     $stmt = $conn->prepare($query);
     $like = '%' . $search . '%';
     $stmt->bind_param('s', $like);
 } else {
-    $query = "SELECT id, username FROM users ORDER BY $sort $order";
+    if ($sort === 'username') {
+        $query = $order === 'DESC'
+            ? "SELECT id, username FROM users ORDER BY username DESC"
+            : "SELECT id, username FROM users ORDER BY username ASC";
+    } else {
+        $query = $order === 'DESC'
+            ? "SELECT id, username FROM users ORDER BY id DESC"
+            : "SELECT id, username FROM users ORDER BY id ASC";
+    }
     $stmt = $conn->prepare($query);
 }
 
@@ -50,4 +61,4 @@ $stmt->close();
 $conn->close();
 
 echo json_encode(['success' => true, 'data' => $users]);
-?>
+?>