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. https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-3456 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-3456
