Qemu : Security Vulnerabilities, CVEs, CVSS score between 5 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 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.

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 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.

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

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.

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/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.

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.

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.

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.

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.

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.

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, scsi_handle_inquiry_reply in hw/scsi/scsi-generic.c allows out-of-bounds write and read operations.

QEMU, through version 2.10 and through version 3.1.0, is vulnerable to an out-of-bounds read of up to 128 bytes in the hw/i2c/i2c-ddc.c:i2c_ddc() function. A local attacker with permission to execute i2c commands could exploit this to read stack memory of the qemu process on the host.

hw/rdma/vmw/pvrdma_cmd.c in QEMU allows create_cq and create_qp memory leaks because errors are mishandled.