QemuCVEs & Vulnerabilities

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.

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.

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.

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.

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.

A flaw was found in QEMU in the implementation of the Pointer Authentication (PAuth) support for ARM introduced in version 4.0 and fixed in version 5.0.0. A general failure of the signature generation process caused every PAuth-enforced pointer to be signed with the same signature. A local attacker could obtain the signature of a protected pointer and abuse this flaw to bypass PAuth protection for all programs running on QEMU.

ati-vga in hw/display/ati.c in QEMU 4.2.0 allows guest OS users to trigger infinite recursion via a crafted mm_index value during an ati_mm_read or ati_mm_write call.

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.

rom_copy() in hw/core/loader.c in QEMU 4.0 and 4.1.0 does not validate the relationship between two addresses, which allows attackers to trigger an invalid memory copy operation.

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.

address_space_map in exec.c in QEMU 4.2.0 can trigger a NULL pointer dereference related to BounceBuffer.

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.

An integer overflow was found in QEMU 4.0.1 through 4.2.0 in the way it implemented ATI VGA emulation. 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 abuse this flaw to crash the QEMU process, resulting in a denial of service.

hw/net/tulip.c in QEMU 4.2.0 has a buffer overflow during the copying of tx/rx buffers because the frame size is not validated against the r/w data length.

hw/display/bochs-display.c in QEMU 4.0.0 does not ensure a sufficient PCI config space allocation, leading to a buffer overflow involving the PCIe extended config space.

QEMU 4.1.0 has a memory leak in zrle_compress_data in ui/vnc-enc-zrle.c during a VNC disconnect operation because libz is misused, resulting in a situation where memory allocated in deflateInit2 is not freed in deflateEnd.

An out-of-bounds heap buffer access flaw was found in the way the iSCSI Block driver in QEMU versions 2.12.0 before 4.2.1 handled a response coming from an iSCSI server while checking the status of a Logical Address Block (LBA) in an iscsi_co_block_status() routine. A remote user could use this flaw to crash the QEMU process, resulting in a denial of service or potential execution of arbitrary code with privileges of the QEMU process on the host.

The virtqueue_map_sg function in hw/virtio/virtio.c in QEMU before 1.7.2 allows remote attackers to execute arbitrary files via a crafted savevm image, related to virtio-block or virtio-serial read.

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.

tftp.c in libslirp 4.1.0, as used in QEMU 4.2.0, does not prevent ..\ directory traversal on Windows.

tcp_emu in tcp_subr.c in libslirp 4.1.0, as used in QEMU 4.2.0, mismanages memory, as demonstrated by IRC DCC commands in EMU_IRC. This can cause a heap-based buffer overflow or other out-of-bounds access which can lead to a DoS or potential execute arbitrary code.

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.

An issue was discovered in ide_dma_cb() in hw/ide/core.c in QEMU 2.4.0 through 4.2.0. The guest system can crash the QEMU process in the host system via a special SCSI_IOCTL_SEND_COMMAND. It hits an assertion that implies that the size of successful DMA transfers there must be a multiple of 512 (the size of a sector). NOTE: a member of the QEMU security team disputes the significance of this issue because a "privileged guest user has many ways to cause similar DoS effect, without triggering this assert.

A flaw was found in the way qemu v1.3.0 and later (virtio-rng) validates addresses when guest accesses the config space of a virtio device. If the virtio device has zero/small sized config space, such as virtio-rng, a privileged guest user could use this flaw to access the matching host's qemu address space and thus increase their privileges on the host.

In QEMU 1:4.1-1, 1:2.1+dfsg-12+deb8u6, 1:2.8+dfsg-6+deb9u8, 1:3.1+dfsg-8~deb10u1, 1:3.1+dfsg-8+deb10u2, and 1:2.1+dfsg-12+deb8u12 (fixed), when executing script in lsi_execute_script(), the LSI scsi adapter emulator advances 's->dsp' index to read next opcode. This can lead to an infinite loop if the next opcode is empty. Move the existing loop exit after 10k iterations so that it covers no-op opcodes as well.

libslirp 4.0.0, as used in QEMU 4.1.0, has a use-after-free in ip_reass in ip_input.c.

qemu-bridge-helper.c in QEMU 3.1 and 4.0.0 does not ensure that a network interface name (obtained from bridge.conf or a --br=bridge option) is limited to the IFNAMSIZ size, which can lead to an ACL bypass.

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

The QMP migrate command in QEMU version 4.0.0 and earlier is vulnerable to OS command injection, which allows the remote 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

tcp_emu in slirp/tcp_subr.c (aka slirp/src/tcp_subr.c) in QEMU 3.0.0 uses uninitialized data in an snprintf call, leading to Information disclosure.

In QEMU 3.1.0, load_device_tree in device_tree.c calls the deprecated load_image function, which has a buffer overflow risk.

interface_release_resource in hw/display/qxl.c in QEMU 3.1.x through 4.0.0 has a NULL pointer dereference.