pci_change_irq_level in hw/pci/pci.c in QEMU before 5.1.1 has a NULL pointer dereference because pci_get_bus() might not return a valid pointer.

fdctrl_write_data in hw/block/fdc.c in QEMU 5.0.0 has a NULL pointer dereference via a NULL block pointer for the current drive.

hw/usb/hcd-ohci.c in QEMU 5.0.0 has an infinite loop when a TD list has a loop.

QEMU 5.0.0 has a heap-based Buffer Overflow in flatview_read_continue in exec.c because hw/sd/sdhci.c mishandles a write operation in the SDHC_BLKSIZE case.

QEMU 5.0.0 has a use-after-free in hw/usb/hcd-xhci.c because the usb_packet_map return value is not checked.

An out-of-bounds read/write access flaw was found in the USB emulator of the QEMU in versions before 5.2.0. This issue occurs while processing USB packets from a guest when USBDevice 'setup_len' exceeds its 'data_buf[4096]' in the do_token_in, do_token_out routines. This flaw allows a guest user to crash the QEMU process, resulting in a denial of service, or the potential execution of arbitrary code with the privileges of the QEMU process on the host.

In QEMU through 5.0.0, an integer overflow was found in the SM501 display driver implementation. This flaw occurs in the COPY_AREA macro while handling MMIO write operations through the sm501_2d_engine_write() callback. A local attacker could abuse this flaw to crash the QEMU process in sm501_2d_operation() in hw/display/sm501.c on the host, resulting in a denial of service.

oss_write in audio/ossaudio.c in QEMU before 5.0.0 mishandles a buffer position.

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.

hw/net/xgmac.c in the XGMAC Ethernet controller in QEMU before 07-20-2020 has a buffer overflow. This occurs during packet transmission and affects the highbank and midway emulated machines. A guest user or process could use this flaw to crash the QEMU process on the host, resulting in a denial of service or potential privileged code execution. This was fixed in commit 5519724a13664b43e225ca05351c60b4468e4555.