During the scan Kayran managed to find that the option of uploading files to the server is enabled.
An attacker can use this vulnerability by abusing the file upload mechanism to upload Malicious Files. He can also upload Webshells and Trojans to the server. In some cases, attackers can use the infected website to store malicious files in order to spread them further on.
File upload vulnerabilities occurs whenever the server accepts a file without validating it properly, or, in cases where there are no certain restrictions on the server.
Make sure that the files are uploaded only in the format you set for them, and, that they are being checked on the server-side according to the files extensions and their signatures.