Yep, that's lens flare.
So the lens hood wasn't large enough and UV filter's won't stop flare
As said don't shoot into the sun .... OR use an object to block direct sun falling on the lens ---- have even used a hand when nothing else availabke ( and then editing it out later )
THe other option is to position yourself so that a natural object provides the shade necessary.
"A woman without curves is like a road without bends, you might get to your destination quicker but the ride is boring as hell'