UDP disadvantages

Lots of possible intrusions

When a socket is receiving data on a UDP port, it will receive packets sent to it by any host, whether it is participating in the application or not

This possibility can present a security problem for some applications that do not robustly distinguish between expected and unexpected packets

Blocking of UDP by your local net administrator

For this reason, many network firewall administrators block UDP data from being sent to a protected host from outside the security perimeter