Buffer overflow in the e1000_receive function in the e1000 device driver (hw/e1000.c) in QEMU 1.3.0-rc2 and other versions, when the SBP and LPE flags are disabled, allows remote attackers to cause a denial of service (guest OS crash) and possibly execute arbitrary guest code via a large packet.
Qemu, as used in Xen 4.0, 4.1 and possibly other products, when emulating certain devices with a virtual console backend, allows local OS guest users to gain privileges via a crafted escape VT100 sequence that triggers the overwrite of a "device model's address space."
The bdrv_open function in Qemu 1.0 does not properly handle the failure of the mkstemp function, when in snapshot node, which allows local users to overwrite or read arbitrary files via a symlink attack on an unspecified temporary file.
The pciej_write function in hw/acpi_piix4.c in the PIIX4 Power Management emulation in qemu-kvm does not check if a device is hotpluggable before unplugging the PCI-ISA bridge, which allows privileged guest users to cause a denial of service (guest crash) and possibly execute arbitrary code by sending a crafted value to the 0xae08 (PCI_EJ_BASE) I/O port, which leads to a use-after-free related to "active qemu timers."