A flaw was found in the way the QEMU-KVM handled erroneous data provided
by the guest Linux virtio-net driver. Due deficiency in the implementation of
the TSO (TCP segment offloading), the guest's virtio-net driver transmitted
improper data to the particular QEMU-KVM process on the host, resulting in its
termination. A remote attacker could use this flaw to cause denial of service
(guest crash) by sending certain, specially-crafted data to arbitrary open port
on the target guest system.

A remote attacker could exploit this to crash guests which use virtio
networking on Linux kernels earlier than 2.6.26.