CVE-2021-27379

An issue was discovered in Xen through 4.11.x, allowing x86 Intel HVM guest OS users to achieve unintended read/write DMA access, and possibly cause a denial of service host OS crash or gain privileges. This occurs because a backport missed a flush, and thus IOMMU updates were not always correct...

Denial Of Service (DoS)

Xen is vulnerable to denial of service DoS. It is allowing x86 Intel HVM guest OS users to cause a host OS denial of service or possibly gain privileges because of insufficient cache write-back under VT-d. When page tables are shared between IOMMU and CPU, changes to them require flushing of both...