If it is a trustee sale auction your are referencing, the lender can postpone the auction while the short sale is being reviewed. There are many variable to this situation in question.
Yes you can still possibly buy a property that is set for auction. For more information, you are encouraged to first seek out the assistance of an experienced, full-time Buyer's Agent Realtor. Otherwise, you'll never know the intentions of the person who is giving you information.
Buyer's Agent Realtor
Technically what you do is write an offer on the auctioned property.
Typically what happens from my experience is these auctioned properties don't actually get sold at auction because the banks minimum is not met.
Would you like more information on how to write an offer?
Signature Realty Group
Scottsdale/Fountain Hills, AZ