An issue was discovered in QEMU through 5.1.0. An out-of-bounds memory access was found in the ATI VGA device implementation. This flaw occurs in the ati_2d_blt() routine in hw/display/ati_2d.c while handling MMIO write operations through the ati_mm_write() callback. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service.

In QEMU through 5.0.0, an assertion failure can occur in the network packet processing. This issue affects the e1000e and vmxnet3 network devices. A malicious guest user/process could use this flaw to abort the QEMU process on the host, resulting in a denial of service condition in net_tx_pkt_add_raw_fragment in hw/net/net_tx_pkt.c.

In QEMU 4.2.0, a MemoryRegionOps object may lack read/write callback methods, leading to a NULL pointer dereference.

QEMU 4.2.0 has a use-after-free in hw/net/e1000e_core.c because a guest OS user can trigger an e1000e packet with the data's address set to the e1000e's MMIO address.

QEMU (aka Quick Emulator), when built with the VGA display emulator support, allows local guest OS privileged users to cause a denial of service (out-of-bounds read and QEMU process crash) via vectors involving display update.

QEMU (aka Quick Emulator), when built with the IDE disk and CD/DVD-ROM Emulator support, allows local guest OS privileged users to cause a denial of service (NULL pointer dereference and QEMU process crash) by flushing an empty CDROM device drive.

The dhcp_decode function in slirp/bootp.c in QEMU (aka Quick Emulator) allows local guest OS users to cause a denial of service (out-of-bounds read and QEMU process crash) via a crafted DHCP options string.

The address_space_write_continue function in exec.c in QEMU (aka Quick Emulator) allows local guest OS privileged users to cause a denial of service (out-of-bounds access and guest instance crash) by leveraging use of qemu_map_ram_ptr to access guest ram block area.

Stack-based buffer overflow in hw/usb/redirect.c in QEMU (aka Quick Emulator) allows local guest OS users to cause a denial of service (QEMU process crash) via vectors related to logging debug messages.

QEMU (aka Quick Emulator) built with the ColdFire Fast Ethernet Controller emulator support is vulnerable to an infinite loop issue. It could occur while receiving packets in 'mcf_fec_receive'. A privileged user/process inside guest could use this issue to crash the QEMU process on the host leading to DoS.

The cirrus_do_copy function in hw/display/cirrus_vga.c in QEMU (aka Quick Emulator), when cirrus graphics mode is VGA, allows local guest OS privileged users to cause a denial of service (divide-by-zero error and QEMU process crash) via vectors involving blit pitch values.

Memory leak in hw/net/eepro100.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (memory consumption and QEMU process crash) by repeatedly unplugging an i8255x (PRO100) NIC device.

The v9fs_iov_vunmarshal function in fsdev/9p-iov-marshal.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (NULL pointer dereference and QEMU process crash) by sending an empty string parameter to a 9P operation.

The rc4030_write function in hw/dma/rc4030.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (divide-by-zero error and QEMU process crash) via a large interval timer reload value.

Memory leak in the ehci_process_itd function in hw/usb/hcd-ehci.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (memory consumption) via a large number of crafted buffer page select (PG) indexes.

The rocker_io_writel function in hw/net/rocker/rocker.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (out-of-bounds read and QEMU process crash) by leveraging failure to limit DMA buffer size.

Memory leak in the v9fs_xattrcreate function in hw/9pfs/9p.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (memory consumption and QEMU process crash) via a large number of Txattrcreate messages with the same fid number.

Memory leak in the v9fs_read function in hw/9pfs/9p.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (memory consumption) via vectors related to an I/O read operation.

Memory leak in the virtio_gpu_resource_create_2d function in hw/display/virtio-gpu.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (memory consumption) via a large number of VIRTIO_GPU_CMD_RESOURCE_CREATE_2D commands.

The serial_update_parameters function in hw/char/serial.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (divide-by-zero error and QEMU process crash) via vectors involving a value of divider greater than baud base.

The pcnet_rdra_addr function in hw/net/pcnet.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) by setting the (1) receive or (2) transmit descriptor ring length to 0.

The imx_fec_do_tx function in hw/net/imx_fec.c in QEMU (aka Quick Emulator) does not properly limit the buffer descriptor count when transmitting packets, which allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via vectors involving a buffer descriptor with a length of 0 and crafted values in bd.flags.

Memory leak in the v9fs_write function in hw/9pfs/9p.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (memory consumption) by leveraging failure to free an IO vector.

Memory leak in the v9fs_link function in hw/9pfs/9p.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (memory consumption) via vectors involving a reference to the source fid object.

The mcf_fec_do_tx function in hw/net/mcf_fec.c in QEMU (aka Quick Emulator) does not properly limit the buffer descriptor count when transmitting packets, which allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via vectors involving a buffer descriptor with a length of 0 and crafted values in bd.flags.

The net_tx_pkt_do_sw_fragmentation function in hw/net/net_tx_pkt.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via a zero length for the current fragment length.

Use-after-free vulnerability in the vmxnet3_io_bar0_write function in hw/net/vmxnet3.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (QEMU instance crash) by leveraging failure to check if the device is active.

The virtqueue_map_desc function in hw/virtio/virtio.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (NULL pointer dereference and QEMU process crash) via a large I/O descriptor buffer length value.

The vmsvga_fifo_run function in hw/display/vmware_vga.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) via vectors related to cursor.mask[] and cursor.image[] array sizes when processing a DEFINE_CURSOR svga command.

The vmxnet_tx_pkt_parse_headers function in hw/net/vmxnet_tx_pkt.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (buffer over-read) by leveraging failure to check IP header length.

The virtqueue_map_desc function in hw/virtio/virtio.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via a zero length for the descriptor buffer.

Integer overflow in the net_tx_pkt_init function in hw/net/net_tx_pkt.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (QEMU process crash) via the maximum fragmentation count, which triggers an unchecked multiplication and NULL pointer dereference.

The mptsas_process_scsi_io_request function in QEMU (aka Quick Emulator), when built with LSI SAS1068 Host Bus emulation support, allows local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) via vectors involving MPTSASRequest objects.

The pvscsi_convert_sglist function in hw/scsi/vmw_pvscsi.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) by leveraging an incorrect cast.

A use-after-free vulnerability was found in the LSI53C895A SCSI Host Bus Adapter emulation of QEMU. The flaw occurs while processing repeated messages to cancel the current SCSI request via the lsi_do_msgout function. This flaw allows a malicious privileged user within the guest to crash the QEMU process on the host, resulting in a denial of service.

The get_cmd function in hw/scsi/esp.c in the 53C9X Fast SCSI Controller (FSC) support in QEMU does not properly check DMA length, which allows local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) via unspecified vectors, involving an SCSI command.

The vmsvga_fifo_run function in hw/display/vmware_vga.c in QEMU allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via a VGA command.

QEMU (aka Quick Emulator) built with the e1000 NIC emulation support is vulnerable to an infinite loop issue. It could occur while processing data via transmit or receive descriptors, provided the initial receive/transmit descriptor head (TDH/RDH) is set outside the allocated descriptor buffer. A privileged user inside guest could use this flaw to crash the QEMU instance resulting in DoS.

The ne2000_receive function in the NE2000 NIC emulation support (hw/net/ne2000.c) in QEMU before 2.5.1 allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via crafted values for the PSTART and PSTOP registers, involving ring buffer control.

QEMU (aka Quick Emulator) built with an IDE AHCI emulation support is vulnerable to a null pointer dereference flaw. It occurs while unmapping the Frame Information Structure (FIS) and Command List Block (CLB) entries. A privileged user inside guest could use this flaw to crash the QEMU process instance resulting in DoS.

The ohci_bus_start function in the USB OHCI emulation support (hw/usb/hcd-ohci.c) in QEMU allows local guest OS administrators to cause a denial of service (NULL pointer dereference and QEMU process crash) via vectors related to multiple eof_timers.

QEMU (aka Quick Emulator) built with the TPR optimization for 32-bit Windows guests support is vulnerable to a null pointer dereference flaw. It occurs while doing I/O port write operations via hmp interface. In that, 'current_cpu' remains null, which leads to the null pointer dereference. A user or process could use this flaw to crash the QEMU instance, resulting in DoS issue.

The is_rndis function in the USB Net device emulator (hw/usb/dev-network.c) in QEMU before 2.5.1 does not properly validate USB configuration descriptor objects, which allows local guest OS administrators to cause a denial of service (NULL pointer dereference and QEMU process crash) via vectors involving a remote NDIS control message packet.

QEMU (aka Quick Emulator) built with the USB EHCI emulation support is vulnerable to a null pointer dereference flaw. It could occur when an application attempts to write to EHCI capabilities registers. A privileged user inside quest could use this flaw to crash the QEMU process instance resulting in DoS.

The virgl_cmd_get_capset function in hw/display/virtio-gpu-3d.c in QEMU (aka Quick Emulator) built with Virtio GPU Device emulator support allows local guest OS users to cause a denial of service (out-of-bounds read and process crash) via a VIRTIO_GPU_CMD_GET_CAPSET command with a maximum capabilities size with a value of 0.

The virtio_gpu_set_scanout function in QEMU (aka Quick Emulator) built with Virtio GPU Device emulator support allows local guest OS users to cause a denial of service (out-of-bounds read and process crash) via a scanout id in a VIRTIO_GPU_CMD_SET_SCANOUT command larger than num_scanouts.

QEMU (aka Quick Emulator) built with a VMWARE VMXNET3 paravirtual NIC emulator support is vulnerable to crash issue. It could occur while reading Interrupt Mask Registers (IMR). A privileged (CAP_SYS_RAWIO) guest user could use this flaw to crash the QEMU process instance resulting in DoS.

The eepro100 emulator in QEMU qemu-kvm blank allows local guest users to cause a denial of service (application crash and infinite loop) via vectors involving the command block list.

QEMU (aka Quick Emulator) built with the Rocker switch emulation support is vulnerable to an off-by-one error. It happens while processing transmit (tx) descriptors in 'tx_consume' routine, if a descriptor was to have more than allowed (ROCKER_TX_FRAGS_MAX=16) fragments. A privileged user inside guest could use this flaw to cause memory leakage on the host or crash the QEMU process instance resulting in DoS issue.

QEMU (aka Quick Emulator) built with a VMWARE VMXNET3 paravirtual NIC emulator support is vulnerable to crash issue. It occurs when a guest sends a Layer-2 packet smaller than 22 bytes. A privileged (CAP_SYS_RAWIO) guest user could use this flaw to crash the QEMU process instance resulting in DoS.