CVE 2016-6351
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.
See the 
CVE page on Mitre.org
for more details.
