Speak to your attorney. Your attorney should be able to help you negotiate that amount and/or a deficiency waiver. Some of my recent short sale closings have been asked to pay the outstanding tax amount, bring money to closing on the 2nd loan, bring funds to closing on the first, etc..
I would speak to an attorney before giving a cent so you know your rights and options.
If you don't want to contact an attorney, you can contact IDHA for free - Illinois Housing Admin. See below for information. They can help you with options too.