Is the wall between a home and an attached garage built as an "exterior wall"?
No, the wall between the home and garage is designed and built as an interior wall. HOWEVER, it is a fire wall. Your code in Oregon requires 1) fire rated door between the spaces, and 2) fire rated wall "assembly", and 3) insulation. 

1) The door needs to be fire rated door and frame, which can be a solid core door and a solid wood frame (not a frame with an applied stop). (See R302.5.)

2) The wall needs one layer of 1/2" gypsum board on the GARAGE side of the wall...other side of wall doesn't matter and 5/8" gypsum board on the ceiling of the garage if habitable rooms are located above the garage. (The building department is worried about a fire starting in the garage, not vise verses. They're protecting the house.) (See Table 302.6.)

3) Insulation is required for the building envelope. 

No other Code items are required for this wall, including shear wall, structural wall, etc. HOWEVER, remember that the garage cannot open directly into a sleeping room (bedroom).