sitting duck
US /ˈsɪtɪŋ dʌk/
UK /ˈsɪtɪŋ dʌk/

1.
alvo fácil, presa fácil
a person or thing that is easy to attack or criticize
:
•
Without proper security, the server was a sitting duck for hackers.
Sem segurança adequada, o servidor era um alvo fácil para hackers.
•
The politician became a sitting duck after his scandal was exposed.
O político se tornou um alvo fácil depois que seu escândalo foi exposto.