libspice, as used in QEMU-KVM in the Hypervisor (aka rhev-hypervisor) in Red Hat Enterprise Virtualization (RHEV) 2.2 and qspice 0.3.0, does not properly validate guest QXL driver pointers, which allows guest OS users to cause a denial of service (invalid pointer dereference and guest OS crash) or possibly gain privileges via unspecified vectors.