Permissions, Privileges, and Access Controls
Xen 4.1 before 4.1.1 and 4.0 before 4.0.2, when using PCI passthrough on Intel VT-d chipsets that do not have interrupt remapping, allows guest OS users to gain host OS privileges by "using DMA to generate MSI interrupts by writing to the interrupt injection registers."
CWE-264 - Permissions Privileges and Access Controls
CWE 264 (permissions, privileges, and access controls) is not a weakness in and of itself, rather it is a category of weaknesses related to the management of permissions, privileges, and other security features used to perform access control. If not addressed, the weaknesses in this category allow attackers to gain privileges for an unintended sphere of control, access sensitive information, and execute arbitrary commands.