Unrestricted Upload of File with Dangerous Type
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.
CWE-434 - Unrestricted Upload of File with dangerous type
'Unrestricted file upload with dangerous type' attacks involve an attacker uploading or transferring files of dangerous types to the server. The severity of such an attack depends upon the execution mechanism and the storage location of the uploaded file. Thus, it may range from simple defacement to arbitrary file execution, and complete system takeover.