Conn. Gen. Stat. § 12-403: Distribution by fiduciary.

No executor, administrator or other person acting in a fiduciary capacity shall be required to transfer, pay over or distribute any property or fund with respect to which a federal or state estate tax is imposed until the amount of such tax or taxes due from the devisee, legatee, heir-at-law, distributee or other person to whom such property is transferred is paid or, if the apportionment of tax has not been determined, until adequate security is furnished by the transferee for such payment.