You stop over exposure, blowing out the details in the whiter/brighter areas, by using proper metering and watching the histogram of the photo. Once you blow out areas of an image....the sensor can not record any details. So there is nothing to recover. That is the same glossy under exposing and having our black in the image....no detail to boost.
There are tons of photo editing apps that will let you cut or boast the exposure ranges in between gross under exposure and blowing out the highlights. Remember that there is relatively little penalty in dropping the exposure in a post processing tool. But if you increase the exposure very much, you are amplifying both the signal and noise (grainy look) of the image.