CVE-2014-3798

The Windows Guest Tools in Citrix XenServer 6.2 SP1 and earlier allows remote attackers to cause a denial of service (guest OS crash) via a crafted Ethernet frame.

CVE-2015-4106

QEMU does not properly restrict write access to the PCI config space for certain PCI pass-through devices, which might allow local x86 HVM guests to gain privileges, cause a denial of service (host crash), obtain sensitive information, or possibly have other unspecified impact via unknown vectors.