We have an idiom for that and we say it "뿌린대로 거둔다." Which means "we harvest as we seeded."

There are many expressions along that line, but not an exact match, I think. This would be the closest in meaning, but it is not used that much in real lie: 남에게 한 대로 되받게 되는 법이다: You're bound to receive what you have done to others. The oft used ones are these: 가는 말이 고와야 오는 말이 곱다: Being nice to others will bring niceness to you too. 뿌린 대로 거두리라: You reap what you sow. 자업자득이다: (same, using Chinese characters)

Well it depends on the context. Suppose A did something bad to B and then something similar happened to A. That's a safe time to use the phrase "what goes around comes around."