Alan, a network administrator, discovered eccouncil video

Full Certification Question

Alan, a network administrator, discovered numerous unfamiliar files in the primary directory of his FTP server. He was particularly intrigued by a binary file labeled "mfs". Alan opted to inspect the FTP server logs, revealing that an anonymous user account had logged into the server, uploaded the files, and executed the script utilizing a function provided by the FTP server software. Additionally, he noticed that the "mfs" file was functioning as a process and actively listening on a network port. What type of vulnerability is likely responsible for enabling this attack?