a sitting duck/target
Something that is unprotected and vulnerable to an easy attack. When my car broke down in a bad neighborhood, I felt like a sitting duck, just waiting to get robbed. We can't go into that area unarmed, we'd be sitting ducks!
Fig. someone or something vulnerable to attack, physical or verbal. (Alludes to a duck floating on the water, not suspecting that it is the object of a hunter or predator. *Typically: be ~; like ~; looking like~.) You look like a sitting duck out there. Get in here where the enemy cannot fire at you. The senator was a sitting duck because of his unpopular position on school reform.
An easy target, as in If you park in front of a fire hydrant, you're a sitting duck for a ticket. This term alludes to the ease with which a hunter can shoot a duck that remains in one spot, in contrast to one in flight. [First half of 1900s]
a sitting duck
If someone is a sitting duck, they are in a situation where it is very easy to attack them or criticize them. A pilot performing this manoeuvre would be a sitting duck for a second enemy aircraft. Note: You can also use sitting-duck before a noun. When the planes reach the sitting-duck warships, the harbour is rocked by a series of huge explosions. Note: A duck is an easy target for hunters when it is sitting on the water or on the ground.
sitting ducka person or thing with no protection against an attack or other source of danger.
a ˌsitting ˈduck/ˈtargeta person or thing that is very easy to attack or criticize: It’s always easy to criticize teachers; they’re just sitting ducks.
n. someone who waits unsuspectingly for doom or destiny; an easy target for something bad. Get out of the way! You’re a sitting duck.