In Android before 2018-04-05 or earlier security patch level on Qualcomm Snapdragon Mobile and Snapdragon Wear MDM9206 MDM9607 MDM9640 MDM9650 QCA6174A QCA6574AU QCA9377 SD 210/SD 212/SD 205 SD 425 SD 600 SD 650/52 SD 808 SD 810 SD 820 and SDX20 lack of input validation for HCI H4 UART packet ID cause system denial of service.