Multiple security issues have been found in the Xen virtualisation solution: CVE-2015-3209 Matt Tait discovered a flaw in the way QEMU"s AMD PCnet Ethernet emulation handles multi-TMD packets with a length above 4096 bytes. A privileged guest user in a guest with an AMD PCNet ethernet card enabled can potentially use this flaw to execute arbitrary code on the host with the privileges of the hosting QEMU process. CVE-2015-4103 Jan Beulich discovered that the QEMU Xen code does not properly restrict write access to the host MSI message data field, allowing a malicious guest to cause a denial of service. CVE-2015-4104 Jan Beulich discovered that the QEMU Xen code does not properly restrict access to PCI MSI mask bits, allowing a malicious guest to cause a denial of service. CVE-2015-4105 Jan Beulich reported that the QEMU Xen code enables logging for PCI MSI-X pass-through error messages, allowing a malicious guest to cause a denial of service. CVE-2015-4106 Jan Beulich discovered that the QEMU Xen code does not properly restrict write access to the PCI config space for certain PCI pass-through devices, allowing a malicious guest to cause a denial of service, obtain sensitive information or potentially execute arbitrary code. CVE-2015-4163 Jan Beulich discovered that a missing version check in the GNTTABOP_swap_grant_ref hypercall handler may result in denial of service. This only applies to Debian stable/jessie. CVE-2015-4164 Andrew Cooper discovered a vulnerability in the iret hypercall handler, which may result in denial of service.