Qemu : Security Vulnerabilities, CVEs, CVSS score between 2 and 5.99

A flaw was found in QEMU. An assertion failure was present in the update_sctp_checksum() function in hw/net/net_tx_pkt.c when trying to calculate the checksum of a short-sized fragmented packet. This flaw allows a malicious guest to crash QEMU and cause a denial of service condition.

QEMU through 8.0.0 could trigger a division by zero in scsi_disk_reset in hw/scsi/scsi-disk.c because scsi_disk_emulate_mode_select does not prevent s->qdev.blocksize from being 256. This stops QEMU and the guest immediately.

QEMU through 8.0.4 accesses a NULL pointer in nvme_directive_receive in hw/nvme/ctrl.c because there is no check for whether an endurance group is configured before checking whether Flexible Data Placement is enabled.

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 flaw was found in QEMU. The async nature of hot-unplug enables a race scenario where the net device backend is cleared before the virtio-net pci frontend has been unplugged. A malicious guest could use this time window to trigger an assertion and cause a denial of service.

A flaw was found in the vhost-vsock device of QEMU. In case of error, an invalid element was not detached from the virtqueue before freeing its memory, leading to memory leakage and other unexpected results. Affected QEMU versions <= 6.2.0.

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.

A flaw was found in the virtio-fs shared file system daemon (virtiofsd) of QEMU. The new 'xattrmap' option may cause the 'security.capability' xattr in the guest to not drop on file write, potentially leading to a modified, privileged executable in the guest. In rare circumstances, this flaw could be used by a malicious user to elevate their privileges within the guest.

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.

An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for versions up to v5.2.0. It may occur if a guest was to supply invalid values for rx/tx queue size or other NIC parameters. A privileged guest user may use this flaw to crash the QEMU process on the host resulting in DoS scenario.

A stack-buffer-overflow was found in QEMU in the NVME component. The flaw lies in nvme_changed_nslist() where a malicious guest controlling certain input can read out of bounds memory. A malicious user could use this flaw leading to disclosure of sensitive information.

A deadlock issue was found in the AHCI controller device of QEMU. It occurs on a software reset (ahci_reset_port) while handling a host-to-device Register FIS (Frame Information Structure) packet from the guest. A privileged user inside the guest could use this flaw to hang the QEMU process on the host, resulting in a denial of service condition. The highest threat from this vulnerability is to system availability.

A flaw was found in the USB redirector device (usb-redir) of QEMU. Small USB packets are combined into a single, large transfer request, to reduce the overhead and improve performance. The combined size of the bulk transfer is used to dynamically allocate a variable length array (VLA) on the stack without proper validation. Since the total size is not bounded, a malicious guest could use this flaw to influence the array length and cause the QEMU process to perform an excessive allocation on the stack, resulting in a denial of service.

The patch for CVE-2020-17380/CVE-2020-25085 was found to be ineffective, thus making QEMU vulnerable to the out-of-bounds read/write access issues previously found in the SDHCI controller emulation code. This flaw allows a malicious privileged guest to crash the QEMU process on the host, resulting in a denial of service or potential code execution. QEMU up to (including) 5.2.0 is affected by this.

A use-after-free flaw was found in the MegaRAID emulator of QEMU. This issue occurs while processing SCSI I/O requests in the case of an error mptsas_free_request() that does not dequeue the request object 'req' from a pending requests queue. This flaw allows a privileged guest user to crash the QEMU process on the host, resulting in a denial of service. Versions between 2.10.0 and 5.2.0 are potentially affected.

A NULL pointer dereference flaw was found in the am53c974 SCSI host bus adapter emulation of QEMU in versions before 6.0.0. This issue occurs while handling the 'Information Transfer' command. This flaw allows a privileged guest user to crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

ide_atapi_cmd_reply_end in hw/ide/atapi.c in QEMU 5.1.0 allows out-of-bounds read access because a buffer index is not validated.

hw/net/e1000e_core.c in QEMU 5.0.0 has an infinite loop via an RX descriptor with a NULL buffer address.

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.

A reachable assertion issue was found in the USB EHCI emulation code of QEMU. It could occur while processing USB requests due to missing handling of DMA memory map failure. A malicious privileged user within the guest may abuse this flaw to send bogus USB requests and crash the QEMU process on the host, resulting in a denial of service.

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

hw/usb/hcd-ohci.c in QEMU 5.0.0 has a stack-based buffer over-read via values obtained from the host controller driver.

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.