The xrstor function in arch/x86/xstate.c in Xen 4.x does not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors, which allows local guest OS users to obtain sensitive register content information from another guest by leveraging pending exception and mask bits. NOTE: this vulnerability exists because of an incorrect fix for CVE-2013-2076.

The PCI backend driver in Xen, when running on an x86 system and using Linux 3.1.x through 4.3.x as the driver domain, allows local guest administrators to generate a continuous stream of WARN messages and cause a denial of service (disk consumption) by leveraging a system with access to a passed-through MSI or MSI-X capable physical PCI device and XEN_PCI_OP_enable_msi operations, aka "Linux pciback missing sanity checks."

Xen 4.6.x and earlier allows local guest administrators to cause a denial of service (host reboot) via vectors related to multiple mappings of MMIO pages with different cachability settings.

The paging_invlpg function in include/asm-x86/paging.h in Xen 3.3.x through 4.6.x, when using shadow mode paging or nested virtualization is enabled, allows local HVM guest users to cause a denial of service (host crash) via a non-canonical guest address in an INVVPID instruction, which triggers a hypervisor bug check.

The PV superpage functionality in arch/x86/mm.c in Xen 3.4.0, 3.4.1, and 4.1.x through 4.6.x allows local PV guests to obtain sensitive information, cause a denial of service, gain privileges, or have unspecified other impact via a crafted page identifier (MFN) to the (1) MMUEXT_MARK_SUPER or (2) MMUEXT_UNMARK_SUPER sub-op in the HYPERVISOR_mmuext_op hypercall or (3) unknown vectors related to page table updates.

The libxl toolstack library in Xen 4.1.x through 4.6.x does not properly release mappings of files used as kernels and initial ramdisks when managing multiple domains in the same process, which allows attackers to cause a denial of service (memory and disk consumption) by starting domains.

The memory_exchange function in common/memory.c in Xen 3.2.x through 4.6.x does not properly release locks, which might allow guest OS administrators to cause a denial of service (deadlock or host crash) via unspecified vectors, related to XENMEM_exchange error handling.

The memory_exchange function in common/memory.c in Xen 3.2.x through 4.6.x does not properly hand back pages to a domain, which might allow guest OS administrators to cause a denial of service (host crash) via unspecified vectors related to domain teardown.

Xen 4.6.x and earlier does not properly enforce limits on page order inputs for the (1) XENMEM_increase_reservation, (2) XENMEM_populate_physmap, (3) XENMEM_exchange, and possibly other HYPERVISOR_memory_op suboperations, which allows ARM guest OS administrators to cause a denial of service (CPU consumption, guest reboot, or watchdog timeout and host reboot) and possibly have unspecified other impact via unknown vectors.

Race condition in the relinquish_memory function in arch/arm/domain.c in Xen 4.6.x and earlier allows local domains with partial management control to cause a denial of service (host crash) via vectors involving the destruction of a domain and using XENMEM_decrease_reservation to reduce the memory of the domain.

Use-after-free vulnerability in QEMU in Xen 4.5.x and earlier does not completely unplug emulated block devices, which allows local HVM guest users to gain privileges by unplugging a block device twice.

The C+ mode offload emulation in the RTL8139 network card device model in QEMU, as used in Xen 4.5.x and earlier, allows remote attackers to read process heap memory via unspecified vectors.

Heap-based buffer overflow in the IDE subsystem in QEMU, as used in Xen 4.5.x and earlier, when the container has a CDROM drive enabled, allows local guest users to execute arbitrary code on the host via unspecified ATAPI commands.

Xen 4.2.x through 4.5.x does not initialize certain fields, which allows certain remote service domains to obtain sensitive information from memory via a (1) XEN_DOMCTL_gettscinfo or (2) XEN_SYSCTL_getdomaininfolist request.

Xen 4.5.x and earlier enables certain default backends when emulating a VGA device for an x86 HVM guest qemu even when the configuration disables them, which allows local guest users to obtain access to the VGA console by (1) setting the DISPLAY environment variable, when compiled with SDL support, or connecting to the VNC server on (2) ::1 or (3) 127.0.0.1, when not compiled with SDL support.

Use-after-free vulnerability in Xen 4.2.x, 4.3.x, and 4.4.x allows remote domains to cause a denial of service (system crash) via a crafted hypercall during HVM guest teardown.

Xen 4.4.x and earlier, when using a large number of VCPUs, does not properly handle read and write locks, which allows local x86 guest users to cause a denial of service (write denial or NMI watchdog timeout and host crash) via a large number of read requests, a different vulnerability than CVE-2014-9065.

common/spinlock.c in Xen 4.4.x and earlier does not properly handle read and write locks, which allows local x86 guest users to cause a denial of service (write denial or NMI watchdog timeout and host crash) via a large number of read requests, a different vulnerability to CVE-2014-9066.

The x86_emulate function in arch/x86/x86_emulate/x86_emulate.c in Xen 4.4.x and earlier does not properly check supervisor mode permissions, which allows local HVM users to cause a denial of service (guest crash) or gain guest kernel mode privileges via vectors involving an (1) HLT, (2) LGDT, (3) LIDT, or (4) LMSW instruction.

Multiple integer overflows in the (1) FLASK_GETBOOL, (2) FLASK_SETBOOL, (3) FLASK_USER, and (4) FLASK_CONTEXT_TO_SID suboperations in the flask hypercall in Xen 4.3.x, 4.2.x, 4.1.x, 3.2.x, and earlier, when XSM is enabled, allow local users to cause a denial of service (processor fault) via unspecified vectors, a different vulnerability than CVE-2014-1892, CVE-2014-1893, and CVE-2014-1894.