A race condition flaw was found in the 9pfs server implementation of QEMU up to and including 5.2.0. This flaw allows a malicious 9p client to cause a use-after-free error, potentially escalating their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity as well as system availability.
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.
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.
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.
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.