The esp_do_dma function in hw/scsi/esp.c in QEMU (aka Quick Emulator), when built with ESP/NCR53C9x controller emulation support, allows local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) or execute arbitrary code on the QEMU host via vectors involving DMA read into ESP command buffer.
https://lists.debian.org/debian-lts-announce/2018/11/msg00038.html
http://www.ubuntu.com/usn/USN-3047-2
http://www.ubuntu.com/usn/USN-3047-1
http://www.securityfocus.com/bid/92119
http://www.openwall.com/lists/oss-security/2016/07/26/7
http://www.openwall.com/lists/oss-security/2016/07/25/14
http://git.qemu.org/?p=qemu.git%3Ba=commit%3Bh=cc96677469388bad3d66479379735cf75db069e3
http://git.qemu.org/?p=qemu.git%3Ba=commit%3Bh=926cde5f3e4d2504ed161ed0cb771ac7cad6fd11