assuming the actual product or the quantity is not prohibited to bring into ICN then you should have no problem.

I believe most countries have consistent security procedures that will allow liquids bought at a duty-free shop to pass through security screening checkpoints as carry-on IF it is sealed in a tamper-evident bag AND it is in original retail packaging AND it is unopened.

In some countries there is no longer actual "international transit" which means you must clear immigration and customs and then go through security screening again to make the connecting flight and therefore you might be required to put the bottle in checked baggage because the connection airport has limitations on liquid container sizes allowed through the screening checkpoint.

If you can put it in checked baggage you should have an even greater chance at success.

Your airline should be able to verify what rules apply for your particular situation.