Fatal error in GF triggered by a visitor

curl -g 'wp-admin/admin.php?page[testing]=1'

PHP Fatal error:  Uncaught TypeError: strtolower(): Argument #1 ($string) must be of type string, array given in /web/app/plugins/gravityforms/gravityforms.php:1735
Stack trace:
#0 /web/app/plugins/gravityforms/gravityforms.php(1735): strtolower()
#1 /web/app/plugins/gravityforms/gravityforms.php(212): GFForms::is_gravity_page()
#2 /web/wp/wp-settings.php(473): include_once('...')
#3 /web/wp-config.php(9): require_once('...')
#4 /web/wp/wp-load.php(55): require_once('...')
#5 /web/wp/wp-admin/admin.php(34): require_once('...')
#6 {main}
  thrown in /web/app/plugins/gravityforms/gravityforms.php on line 1735
  1. I don’t think this code must be run in the first place (a visitor accessing an admin page shouldn’t trigger the hook’s stack)

  2. user input is not correctly cleaned (it’s fine assuming page is a string, but handling the case it’s not is even better).

Please open a support ticket at: https://www.gravityforms.com/open-support-ticket/technical/