Xen 4.x, when using Intel VT-d for a bus mastering capable PCI device, does not properly check the source when accessing a bridge device's interrupt remapping table entries for MSI interrupts, which allows local guest domains to cause a denial of service (interrupt injection) via unspecified vectors.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.