An array index bounds overrun flaw has been discovered in the vmxnet3 device
as emulated by qemu.
A privileged guest user could use this flaw to corrupt qemu process' memory on the host, which could potentially result in arbitrary code execution on the host with the privileges of the qemu process.
This issue was discovered by Michael S. Tsirkin of Red Hat.
Created qemu tracking bugs for this issue:
Affects: fedora-all [bug 1087522]
qemu-1.6.2-4.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.