TFTP

TFTP: Minimal file transfer protocol over UDP, without authentication and without directory listing. It is widely used to distribute configurations and firmware and operates without any authenticationAuthenticationVerification of the claimed identity of a user or system..

How it works and where it fits

TFTP per RFC 1350 runs on UDP port 69 and knows only two operations: read a file and write a file. There are no user accounts, no permissions, and no way to list a directory. To retrieve a file you must know its exact name. The protocol is used for network boot, firmware rollout, and automated configuration backups of network and field devices.

Practical security relevance

The absence of listing invites the fallacy that a TFTP server is harmless without knowledge of file names. In reality the names usually come from elsewhere: backup logs, documentation, naming conventions, or patterns guessable from device identifiers. Since saved configurations regularly contain credentials and network structure, TFTP belongs strictly on isolated management networks and, where possible, should be replaced by SFTP or SCP.

Related concepts

• Network AccessNetwork AccessThe ability of a user, device, or workload to connect to and use network resources.: The ability of a user, device, or workload to connect to and use network resources.
• EnumerationEnumerationIdentifies users, services, shares, or other resources of a target system.: Identifies users, services, shares, or other resources of a target system.
• Operational Technology SecurityOperational Technology SecurityProtects industrial control, production, and process control systems.: Protects industrial control, production, and process control systems.
• AuthenticationAuthenticationVerification of the claimed identity of a user or system.: Verification of the claimed identity of a user or system.