Mo. Rev. Stat. § 443.420
No party shall have the right of redeeming from any such sale as set forth in section 443.410 unless he shall have given the written notice specified in said section and shall within twenty days after such sale give security to the satisfaction of the circuit court of the county in which the land is located for the payment of the interest on the debt or obligation secured by the mortgage deed of trust under which the sale is made to accrue within such year after the sale is made, and for the payment in full of the legal charges and costs of the sale, and for the payment of all interest accrued prior to the sale or thereafter which the purchaser at the sale or his representatives or assigns may pay on any prior encumbrance on the land, as well as the interest which may accrue thereon during such year allowed for redemption whether so paid or not and all taxes and assessments and interest and costs thereon whether general or special accrued or accruing during such year allowed for redemption and whether paid by the purchaser at the sale or not together with interest at rate of six percent per annum on all sums so paid by the purchaser or those claiming under him and for damages for all waste committed or suffered by the party giving such security or those claiming under him during such year unless said property is so redeemed, and it shall be necessary to pay for such redemption all such sums to which the purchaser or those claiming under him should be entitled with interest as aforesaid. Said security shall be by bond executed by the person or persons so entitled to redeem with at least one good surety in a sum amply sufficient to cover the aggregate of all said sums exclusive of the principal debt or obligation, but including damages and interest, to be so absolutely paid in event redemption is not made and the aggregate of all such shall be the measure of damages to be paid in satisfaction of said bond if such redemption is not made.
§ 443.420, RSMo