How do you fix a cracked foundation?

I have a hairline crack that goes from the bottom of my window seal all the way down to the ground, which is allowing water to get in and damage my drywall, how do you repair this crack without making it obvious that there was damage in the first place? I don't want to use anything that will show that I'm covering something up because I plan on selling my house in a few years and I just know a home inspector will catch it. Any ideas?