Monstra CMS 3.0.4 allows remote authenticated users to upload and execute arbitrary PHP code via admin/index.php?id=filesmanager because, for example, .php filenames are blocked but .php7 filenames are not, a related issue to CVE-2017-18048.

Monstra CMS through 3.0.4 has an incomplete "forbidden types" list that excludes .php (and similar) file extensions but not the .pht or .phar extension, which allows remote authenticated Admins or Editors to execute arbitrary PHP code by uploading a file, a different vulnerability than CVE-2017-18048.

Monstra CMS 3.0.4 allows users to upload arbitrary files, which leads to remote command execution on the server, for example because .php (lowercase) is blocked but .PHP (uppercase) is not.