A heap buffer overflow was found in the floppy disk emulator of QEMU up to 6.0.0 (including). It could occur in fdctrl_transfer_handler() in hw/block/fdc.c while processing DMA read data transfers from the floppy drive to the guest system. A privileged guest user could use this flaw to crash the QEMU process on the host resulting in DoS scenario, or potential information leakage from the host memory.
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 potential stack overflow via infinite loop issue was found in various NIC emulators of QEMU in versions up to and including 5.2.0. The issue occurs in loopback mode of a NIC wherein reentrant DMA checks get bypassed. A guest user/process may use this flaw to consume CPU cycles or crash the QEMU process on the host resulting in DoS scenario.
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.
USN-4467-1 fixed vulnerabilities in QEMU. The fix for CVE-2020-13754
introduced a regression in certain environments. This update fixes the
problem.
We apologize for the inconvenience.
Original advisory details:
Ren Ding, Hanqing Zhao, Alexander Bulekov, and Anatoly Trosinenko
discovered that the QEMU incorrectly handled certain msi-x mmio operations.
An attacker inside a guest could possibly use this issue to cause QEMU to
crash, resulting in a denial of service. (CVE-2020-13754)
A heap-based buffer overflow was found in QEMU through 5.0.0 in the SDHCI device emulation support. It could occur while doing a multi block SDMA transfer via the sdhci_sdma_transfer_multi_blocks() routine in hw/sd/sdhci.c. A guest user or process could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition, or potentially execute arbitrary code with privileges of the QEMU process on the host.
iscsi_aio_ioctl_cb in block/iscsi.c in QEMU 4.1.0 has a heap-based buffer over-read that may disclose unrelated information from process memory to an attacker.
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.
eth_get_gso_type in net/eth.c in QEMU 4.2.1 allows guest OS users to trigger an assertion failure. A guest can crash the QEMU process via packet data that lacks a valid Layer 3 protocol.
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 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.
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.