Mass. Gen. Laws ch. 167B, § 11: Waiver of rights

Section 11. No writing or other agreement between a consumer and any other person may contain any provision which constitutes a waiver of any right conferred or cause of action created by this chapter. Nothing in this section prohibits, however, any writing or other agreement which grants to a consumer a more extensive right or remedy or greater protection than contained in this chapter or a waiver given in settlement of a dispute or action.