The (1) XENMEM_decrease_reservation, (2) XENMEM_populate_physmap, and (3) XENMEM_exchange hypercalls in Xen 4.2 and earlier allow local guest administrators to cause a denial of service (long loop and hang) via a crafted extent_order value.

The handle_mmio function in arch/x86/hvm/io.c in the MMIO operations emulator for Xen 3.3 and 4.x, when running an HVM guest, does not properly reset certain state information between emulation cycles, which allows local guest OS users to cause a denial of service (guest OS crash) via unspecified operations on MMIO regions.

tools/libxc/xc_dom_bzimageloader.c in Xen 3.2, 3.3, 4.0, and 4.1 allows local users to cause a denial of service (management software infinite loop and management domain resource consumption) via unspecified vectors related to "Lack of error checking in the decompression loop."

Multiple integer overflows in tools/libxc/xc_dom_bzimageloader.c in Xen 3.2, 3.3, 4.0, and 4.1 allow local users to cause a denial of service and possibly execute arbitrary code via a crafted paravirtualised guest kernel image that triggers (1) a buffer overflow during a decompression loop or (2) an out-of-bounds read in the loader involving unspecified length fields.

The fixup_page_fault function in arch/x86/traps.c in Xen 4.0.1 and earlier on 64-bit platforms, when paravirtualization is enabled, does not verify that kernel mode is used to call the handle_gdt_ldt_mapping_fault function, which allows guest OS users to cause a denial of service (host OS BUG_ON) via a crafted memory access.

The do_block_io_op function in (1) drivers/xen/blkback/blkback.c and (2) drivers/xen/blktap/blktap.c in Xen before 3.4.0 for the Linux kernel 2.6.18, and possibly other versions, allows guest OS users to cause a denial of service (infinite loop and CPU consumption) via a large production request index to the blkback or blktap back-end drivers. NOTE: some of these details are obtained from third party information.

The backend driver in Xen 3.x allows guest OS users to cause a denial of service via a kernel thread leak, which prevents the device and guest OS from being shut down or create a zombie domain, causes a hang in zenwatch, or prevents unspecified xm commands from working properly, related to (1) netback, (2) blkback, or (3) blktap.

The pyGrub boot loader in Xen 3.0.3, 3.3.0, and Xen-3.3.1 does not support the password option in grub.conf for para-virtualized guests, which allows attackers with access to the para-virtualized guest console to boot the guest or modify the guest's kernel boot parameters without providing the expected password.

The hypervisor_callback function in Xen, possibly before 3.4.0, as applied to the Linux kernel 2.6.30-rc4, 2.6.18, and probably other versions allows guest user applications to cause a denial of service (kernel oops) of the guest OS by triggering a segmentation fault in "certain address ranges."

xend in Xen 3.3.0 does not properly restrict a guest VM's write access within the /local/domain xenstore directory tree, which allows guest OS users to cause a denial of service and possibly have unspecified other impact by writing to (1) console/tty, (2) console/limit, or (3) image/device-model-pid. NOTE: this issue exists because of erroneous set_permissions calls in the fix for CVE-2008-4405.