The Floppy Disk Controller (FDC) in QEMU, as used in Xen 4.5.x and earlier and KVM, allows local guest users to cause a denial of service (out-of-bounds write and guest crash) or possibly execute arbitrary code via the (1) FD_CMD_READ_ID, (2) FD_CMD_DRIVE_SPECIFICATION_COMMAND, or other unspecified commands, aka VENOM.
Exploitability
AV:AAC:LAu:SImpact
C:CI:CA:C7.7/AV:A/AC:L/Au:S/C:C/I:C/A:C