Roxy Fileman 1.4.6 allows Remote Code Execution via a .phar upload, because the default FORBIDDEN_UPLOADS value in conf.json only blocks .php, .php4, and .php5 files. (Visiting any .phar file invokes the PHP interpreter in some realistic web-server configurations.)
Roxy Fileman 1.4.5 for .NET is vulnerable to path traversal. A remote attacker can write uploaded files to arbitrary locations via the RENAMEFILE action. This can be leveraged for code execution by uploading a specially crafted Windows shortcut file and writing the file to the Startup folder (because an incomplete blacklist of file extensions allows Windows shortcut files to be uploaded).