Internet TCP port 20 is primarily used for the data transfer process in the File Transfer Protocol (FTP). FTP, a standard network protocol, is used for the transfer of computer files between a client and server on a computer network. FTP uses two ports: 21 for command control and 20 for data traffic. Examples of software that use this protocol include FileZilla, WinSCP, and Cyberduck.
TCP port 20 is traditionally used for FTP data transfers. In the past, hackers have exploited this port to perform unauthorized data transfers or manipulate data being transferred. They have also used it to gain unauthorized access to systems by exploiting vulnerabilities in the FTP service. Additionally, port 20 has been used in FTP bounce attacks, where an attacker uses the port to mask their identity and location. This port can also be used in Distributed Denial of Service (DDoS) attacks, where multiple compromised systems are used to flood a target system, causing it to become unavailable.
