Are outlets near kitchen sink required to be protected by GFCI?
Yes, kitchen receptacles near the sink need to be GFCI protected. Since you don't have GFCI at that location, there are three possibilities to consider:


They are protected at the circuit breaker with a combination circuit breaker/GFCI. The downside to circuit breaker/GFCI is that resetting it is not as convenient as at point-of-use.
They are protected elsewhere in the circuit. If you have some GFCI receptacles in the kitchen but others that are non-GFCI, you may find that tripping (use the TEST button) the GFCI receptacles actually cuts power to the non-GFCI receptacles as well.
Not protected! This is legal as long as the receptacles were installed before the GFCI requirements were put in place. That being said, retrofit is generally very easy and inexpensive. The complication you have is the "4 plug outlets". Those are likely 2 standard dual-receptacles underneath the faceplate. If they are all on the same circuit then you can replace just one of them with a GFCI/receptacle and connect the other regular receptacle to the "load" screws on the GFCI. If they are two separate circuits then you will need two GFCI/receptacle devices. In either case, you will need a new faceplate unless the existing receptacles are "Decora" style.