A PHP application running on the remote web server is affected by a remote code execution vulnerability.
According to its self-reported version, the instance of Drupal running on the remote web server is 7.x prior to 7.58, 8.3.x prior to 8.3.9, 8.4.x prior to 8.4.6, or 8.5.x prior to 8.5.1. It is, therefore, affected by a remote code execution vulnerability. Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Upgrade to Drupal version 7.58 / 8.3.9 / 8.4.6 / 8.5.1 or later.