An user able to alter the savevm data (either on the disk or over the wire during migration) could use this flaw to to corrupt QEMU process memory on the (destination) host, which could potentially result in arbitrary code execution on the host with the privileges of the QEMU process.

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.

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 QEMU in the uefi-vars virtual device. When the guest writes to register UEFI_VARS_REG_BUFFER_SIZE, the .write callback `uefi_vars_write` is invoked. The function allocates a heap buffer without zeroing the memory, leaving the buffer filled with residual data from prior allocations. When the guest later reads from register UEFI_VARS_REG_PIO_BUFFER_TRANSFER, the .read callback `uefi_vars_read` returns leftover metadata or other sensitive process memory from the previously allocated buffer, leading to an information disclosure vulnerability.

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 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.

A heap buffer overflow was found in the virtio-snd device in QEMU. When reading input audio in the virtio-snd input callback, virtio_snd_pcm_in_cb, the function did not check whether the iov can fit the data buffer. This issue can trigger an out-of-bounds write if the size of the virtio queue element is equal to virtio_snd_pcm_status, which makes the available space for audio data zero.

A heap-based buffer overflow was found in the SDHCI device emulation of QEMU. The bug is triggered when both `s->data_count` and the size of `s->fifo_buffer` are set to 0x200, leading to an out-of-bound access. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition.