Integer overflow in the VNC display driver in QEMU before 2.1.0 allows attachers to cause a denial of service (process crash) via a CLIENT_CUT_TEXT message, which triggers an infinite loop.

The virtqueue_map_sg function in hw/virtio/virtio.c in QEMU before 1.7.2 allows remote attackers to execute arbitrary files via a crafted savevm image, related to virtio-block or virtio-serial read.

An off-by-one error was found in QEMU's KVM Xen guest support. A malicious guest could use this flaw to trigger out-of-bounds heap accesses in the QEMU process via the emulated Xen physdev hypercall interface, leading to a denial of service or potential memory corruption.

A flaw was found in the virtio-crypto device of QEMU. A malicious guest operating system can exploit a missing length limit in the AKCIPHER path, leading to uncontrolled memory allocation. This can result in a denial of service (DoS) on the host system by causing the QEMU process to terminate unexpectedly.

Shadow mode tracing code uses a set of per-CPU variables to avoid cumbersome parameter passing. Some of these variables are written to with guest controlled data, of guest controllable size. That size can be larger than the variable, and bounding of the writes was missing.

In the context switch logic Xen attempts to skip an IBPB in the case of a vCPU returning to a CPU on which it was the previous vCPU to run. While safe for Xen's isolation between vCPUs, this prevents the guest kernel correctly isolating between tasks. Consider: 1) vCPU runs on CPU A, running task 1. 2) vCPU moves to CPU B, idle gets scheduled on A. Xen skips IBPB. 3) On CPU B, guest kernel switches from task 1 to 2, issuing IBPB. 4) vCPU moves back to CPU A. Xen skips IBPB again. Now, task 2 is running on CPU A with task 1's training still in the BTB.

A flaw was found in QEMU. If the QIOChannelWebsock object is freed while it is waiting to complete a handshake, a GSource is leaked. This can lead to the callback firing later on and triggering a use-after-free in the use of the channel. This can be abused by a malicious client with network access to the VNC WebSocket port to cause a denial of service during the WebSocket handshake prior to the VNC client authentication.

A flaw was found in the virtio-net device in QEMU. When enabling the RSS feature on the virtio-net network card, the indirections_table data within RSS becomes controllable. Setting excessively large values may cause an index out-of-bounds issue, potentially resulting in heap overflow access. This flaw allows a privileged user in the guest to crash the QEMU process on the host.

A flaw was found in QEMU. An assertion failure was present in the usb_ep_get() function in hw/net/core.c when trying to get the USB endpoint from a USB device. This flaw may allow a malicious unprivileged guest user to crash the QEMU process on the host and cause a denial of service condition.

A flaw was found in the QEMU NBD Server. This vulnerability allows a denial of service (DoS) attack via improper synchronization during socket closure when a client keeps a socket open as the server is taken offline.