Use-after-free vulnerability in the vmxnet3_io_bar0_write function in hw/net/vmxnet3.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (QEMU instance crash) by leveraging failure to check if the device is active. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-6833