Mass. Gen. Laws ch. 231 § 13A
Any judgment entered in an action upon a contract, promissory note or other instrument in which or in a memorandum or writing relating to which is contained a stipulation, whereby the defendant in such action waived or agreed to waive or authorized another person to waive or agree to waive the issue or service of process in such an action shall be set aside or vacated on motion of the defendant, unless it appears that service in the usual manner was had upon him or that the plaintiff sent to him by registered mail at least seven days before the entry of such action a notice of his intention to enter the same on said day and at the time of entry filed an affidavit of giving notice as aforesaid, which affidavit shall be prima facie evidence of the giving thereof. Any stipulation in a contract, promissory note or other instrument, or in any memorandum or writing relating thereto, whereby a party thereto agrees to confess judgment in any action which may be brought thereon or authorizes or agrees to authorize another person to confess judgment as aforesaid shall be void and any judgment by confession taken in pursuance of such a stipulation shall be set aside or vacated on motion of the defendant. When a judgment is set aside or vacated under the authority of this section, all outstanding executions issued thereon shall be stayed or superseded without security.
Mass. Gen. Laws ch. 231, § 13A