An assertion failure issue was found in the Network Block Device(NBD) Server in all QEMU versions before QEMU 5.0.1. This flaw occurs when an nbd-client sends a spec-compliant request that is near the boundary of maximum permitted request length. A remote nbd-client could use this flaw to crash the qemu-nbd server resulting in a denial of service.
hw/pci/pci.c in QEMU 4.2.0 allows guest OS users to trigger an out-of-bounds access by providing an address near the end of the PCI configuration space.
In QEMU 5.0.0 and earlier, megasas_lookup_frame in hw/scsi/megasas.c has an out-of-bounds read via a crafted reply_queue_head field from a guest OS user.
In QEMU 5.0.0 and earlier, es1370_transfer_audio in hw/audio/es1370.c does not properly validate the frame count, which allows guest OS users to trigger an out-of-bounds access during an es1370_write() operation.
sd_wp_addr in hw/sd/sd.c in QEMU 4.2.0 uses an unvalidated address, which leads to an out-of-bounds read during sdhci_write() operations. A guest OS user can crash the QEMU process.
A potential DoS flaw was found in the virtio-fs shared file system daemon (virtiofsd) implementation of the QEMU version >= v5.0. Virtio-fs is meant to share a host file system directory with a guest via virtio-fs device. If the guest opens the maximum number of file descriptors under the shared directory, a denial of service may occur. This flaw allows a guest user/process to cause this denial of service on the host.
Stack-based buffer overflow in the vrend_decode_set_framebuffer_state function in vrend_decode.c in virglrenderer before 926b9b3460a48f6454d8bbe9e44313d86a65447f, as used in Quick Emulator (QEMU), allows a local guest users to cause a denial of service (application crash) via the "nr_cbufs" argument.