A flaw was found in the QEMU built-in VNC server while processing ClientCutText messages. The qemu_clipboard_request() function can be reached before vnc_server_cut_text_caps() was called and had the chance to initialize the clipboard peer, leading to a NULL pointer dereference. This could allow a malicious authenticated VNC client to crash QEMU and trigger a denial of service.

A stack based buffer overflow was found in the virtio-net device of QEMU. This issue occurs when flushing TX in the virtio_net_flush_tx function if guest features VIRTIO_NET_F_HASH_REPORT, VIRTIO_F_VERSION_1 and VIRTIO_NET_F_MRG_RXBUF are enabled. This could allow a malicious user to overwrite local variables allocated on the stack. Specifically, the `out_sg` variable could be used to read a part of process memory and send it to the wire, causing an information leak.

A bug in QEMU could cause a guest I/O operation otherwise addressed to an arbitrary disk offset to be targeted to offset 0 instead (potentially overwriting the VM's boot code). This could be used, for example, by L2 guests with a virtual disk (vdiskL2) stored on a virtual disk of an L1 (vdiskL1) hypervisor to read and/or write data to LBA 0 of vdiskL1, potentially gaining control of L1 at its next reboot.

A heap out-of-bounds memory read flaw was found in the virtual nvme device in QEMU. The QEMU process does not validate an offset provided by the guest before computing a host heap pointer, which is used for copying data back to the guest. Arbitrary heap memory relative to an allocated buffer can be disclosed.

A flaw was found in the QEMU virtual crypto device while handling data encryption/decryption requests in virtio_crypto_handle_sym_req. There is no check for the value of `src_len` and `dst_len` in virtio_crypto_sym_op_helper, potentially leading to a heap buffer overflow when the two values differ.

A DMA reentrancy issue leading to a use-after-free error was found in the e1000e NIC emulation code in QEMU. This issue could allow a privileged guest user to crash the QEMU process on the host, resulting in a denial of service.

A flaw was found in the 9p passthrough filesystem (9pfs) implementation in QEMU. When a local user in the guest writes an executable file with SUID or SGID, none of these privileged bits are correctly dropped. As a result, in rare circumstances, this flaw could be used by malicious users in the guest to elevate their privileges within the guest and help a host local user to elevate privileges on the host.

A flaw was found in the QEMU built-in VNC server. When a client connects to the VNC server, QEMU checks whether the current number of connections crosses a certain threshold and if so, cleans up the previous connection. If the previous connection happens to be in the handshake phase and fails, QEMU cleans up the connection again, resulting in a NULL pointer dereference issue. This could allow a remote unauthenticated client to cause a denial of service.

A stack overflow via an infinite recursion vulnerability was found in the eepro100 i8255x device emulator of QEMU. This issue occurs while processing controller commands due to a DMA reentry issue. This flaw allows a guest user or process to consume CPU cycles or crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

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.