Xen 4.2.x, 4.1.x, and 4.0, when using Intel VT-d for PCI passthrough, does not properly configure VT-d when supporting a device that is behind a legacy PCI Bridge, which allows local guests to cause a denial of service to other guests by injecting an interrupt.
Exploitability
AV:AAC:LAu:NImpact
C:NI:NA:C6.1/AV:A/AC:L/Au:N/C:N/I:N/A:C