It is almost impossible to determine what the rose is from a couple of bloom photos. I can only suggest you add photos of the bare winter bush, the summer bush, foliage, a leaf on your hand for size comparison, hips, bloom side-on showing pedicel, prickles, etc. Then you need to tell us of any susceptibility to disease, how many petals, how wide the average bloom is, and absolutely anything else you can think of that will help identify your foundling.