Pennsylvania Statutes Title 15 Pa.C.S.A. Corporations and Unincorporated Associations § 1503. Defense of ultra vires

(1) In an action by a shareholder against the corporation to enjoin the doing of unauthorized acts or the transaction or continuation of unauthorized business.  If the unauthorized acts or business sought to be enjoined are being transacted pursuant to any contract to which the corporation is a party, the court may, if all of the parties to the contract are parties to the action and if it deems the result to be equitable, set aside and enjoin the performance of the contract, and in so doing shall allow to the corporation, or to the other parties to the contract, as the case may be, such compensation as may be appropriate for the loss or damage sustained by any of them from the action of the court in setting aside and enjoining the performance of the contract, but anticipated profits to be derived from the performance of the contract shall not be awarded by the court as a loss or damage sustained.

(2) In any action by or in the right of the corporation to procure a judgment in its favor against an incumbent or former officer or director of the corporation for loss or damage due to his unauthorized acts.

(3) In a proceeding by the Commonwealth under section 503 (relating to actions to revoke corporate franchises) or in a proceeding by the Commonwealth to enjoin the corporation from the doing of unauthorized or unlawful business.