hw/ide/pci.c in QEMU before 5.1.1 can trigger a NULL pointer dereference because it lacks a pointer check before an ide_cancel_dma_sync call.

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.

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.

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

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.

hw/pci/msix.c in QEMU 4.2.0 allows guest OS users to trigger an out-of-bounds access via a crafted address in an msi-x mmio operation.

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.

The process_tx_desc function in hw/net/e1000.c in QEMU before 2.4.0.1 does not properly process transmit descriptor data when sending a network packet, which allows attackers to cause a denial of service (infinite loop and guest crash) via unspecified vectors.

Buffer overflow in the send_control_msg function in hw/char/virtio-serial-bus.c in QEMU before 2.4.0 allows guest users to cause a denial of service (QEMU process crash) via a crafted virtio control message.

The ne2000_receive function in hw/net/ne2000.c in QEMU before 2.4.0.1 allows attackers to cause a denial of service (infinite loop and instance crash) or possibly execute arbitrary code via vectors related to receiving packets.

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.

Qemu 1.1.2+dfsg to 2.1+dfsg suffers from a buffer overrun which could potentially result in arbitrary code execution on the host with the privileges of the QEMU process.

** DISPUTED ** The QMP guest_exec command in QEMU 4.0.0 and earlier is prone to OS command injection, which allows the attacker to achieve code execution, denial of service, or information disclosure by sending a crafted QMP command to the listening server. Note: This has been disputed as a non-issue since QEMU's -qmp interface is meant to be used by trusted users. If one is able to access this interface via a tcp socket open to the internet, then it is an insecure configuration issue.