Those alternative protocols I mentioned before? SFTP and SCP are two of them.
If you have the capability to use the secure protocols instead of TFTP, do it, just make sure you have trusted software like SolarWinds SFTP/SCP Server.
Like the TFTP Server software, SolarWinds SFTP/SCP Server is multi-threaded and commonly used to upload and download executable images and back-up configurations for routers and switches. You can authorize specific IPs or ranges to limit sending and receiving directly to the server for advanced security, and run it as a service on a centralized server.
More Information and Official Website:
Download link: https://www.solarwinds.com/free-tools/free-sftp-server