The question to ask is not whether it is doable, but the consequences to you of a delay. 33 minutes is 3 minutes over the MCT, the time which UA sets as the minimum for which it is willing to accept the risks of a misconnect. But, it is under the SCT (sensible connection time) if you have any need to be at your destination on time.

What is the next flight and does it have availability? UA will need to rebook you onto that flight and over the holidays, it might not be the next flight. Given that UA requires you to board your onward flight no later than T-15 (domestic), you have 18 minutes from the time the inbound flight's brakes lock at the gate, to deplane and head to your nearby onward gate.

Any delay and you will likely misconnect.