Starbucks: Reflected XSS in https://www.starbucks.com/account/create/redeem/MCP131XSR via xtl_amount, xtl_coupon_code, xtl_amount_type parameters

HI, Summary: Reflected XSS Description: the parameters are complementary to each other Platforms Affected: my browser firefox 52.7.3 Steps To Reproduce: 1. go to https://www.starbucks.com/account/create/redeem/MCP131XSR?xtlcouponcode=1&xtlcouponcode=81431&xtlamount=0.0&xtlamounttype=DOLLARVALUE 1...