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Fencer Vulns
medium 4.9

CVE-2023-6693 json

Qemu: virtio-net: stack buffer overflow in virtio_net_flush_tx()

published 2024-01-02 2 y ago modified 2026-11-05 3 d ago also EUVD-2023-58914

cvss
4.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 26%
public exploits
0
none known

Summary

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.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 8 8100020240314161907.e155f54d
  • Red Hat Red Hat Enterprise Linux 9 17:9.0.0-10.el9_5.3
  • qemu Debian 12 1:7.2+dfsg-7+deb12u4
  • qemu Debian 14, Debian 13 1:8.2.0+ds-3

debian advisories DEBIAN-CVE-2023-6693

  • qemu Ubuntu 22.04 LTS 1:6.2+dfsg-2ubuntu6.22

ubuntu advisories UBUNTU-CVE-2023-6693

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • qemu-kvm RHEL 9 17:9.0.0-10.el9_5.3
  • qemu-img RHEL 9 17:9.0.0-10.el9_5.3
  • qemu-kvm-core RHEL 9 17:9.0.0-10.el9_5.3
  • qemu-kvm-tools RHEL 9 17:9.0.0-10.el9_5.3
  • qemu-pr-helper RHEL 9 17:9.0.0-10.el9_5.3
  • qemu-kvm-common RHEL 9 17:9.0.0-10.el9_5.3
  • qemu-guest-agent RHEL 9 17:9.0.0-10.el9_5.3
  • qemu-kvm-audio-pa RHEL 9 17:9.0.0-10.el9_5.3

red hat advisories RHSA-2025:4492RHSA-2024:2962

  • qemu SLES for SAP 12 SP5, SLES 12 SP5 3.1.1.1-75.1
  • qemu SLE Module for Server Applications 15 SP5, SLE Module for Package Hub 15 SP5, SLE Module for Basesystem 15 SP5 +2 more 7.1.0-150500.49.12.1

suse advisories SUSE-SU-2024:3229-1SUSE-SU-2024:1103-1

  • qemu openSUSE Tumbleweed 8.2.1-1.1

opensuse advisories openSUSE-SU-2024:13705-1

  • qemu-kvm Rocky Linux 9 7:9.0.0-10.el9_5.3
  • hivex Rocky Linux 8 1.3.18-23.module+el8.10.0+1590+a67ab969
  • netcf Rocky Linux 8 0.2.8-12.module+el8.10.0+1590+a67ab969
  • swtpm Rocky Linux 8 0.7.0-4.20211109gitb79fd91.module+el8.10.0+1590+a67ab969
  • libnbd Rocky Linux 8 1.6.0-5.module+el8.10.0+1590+a67ab969
  • nbdkit Rocky Linux 8 1.24.0-5.module+el8.10.0+1590+a67ab969
  • libtpms Rocky Linux 8 0.9.1-2.20211126git1ff6fe1f43.module+el8.10.0+1590+a67ab969
  • libvirt Rocky Linux 8 8.0.0-23.1.module+el8.10.0+1779+84732956

rocky linux advisories RLSA-2025:4492RLSA-2024:2962

  • qemu CBL-Mariner 2.0 6.2.0-21
  • qemu Azure Linux 3.0 8.2.0-13

azure linux advisories AZL-35675AZL-35676

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-6693 updated cvss 4.9

QEMU: virtio-net: stack buffer overflow in virtio_net_flush_tx()

  • Red Hat Enterprise Linux 6 qemu-img, qemu-kvm, qemu-kvm-tools, qemu-guest-agent, qemu-guest-agent-win32 Red Hat Enterprise Linux 7 qemu-img, qemu-kvm, libcacard, qemu-img-ma, qemu-kvm-ma, qemu-kvm-tools, +5 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 Advanced Virtualization qemu-img, qemu-kvm, qemu-kiwi, qemu-kvm-core, qemu-kvm-tests, qemu-kvm-common, +9 more
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AppStream (v. 8) libnbd 1.6.0-5.module+el8.9.0+18724+20190c23, netcf 0.2.8-12.module+el8.9.0+18724+20190c23, hivex 1.3.18-23.module+el8.9.0+18724+20190c23, nbdfuse 1.6.0-5.module+el8.9.0+18724+20190c23, nbdkit 1.24.0-5.module+el8.9.0+18724+20190c23, seabios 1.16.0-4.module+el8.9.0+19570+14a90618, +104 more
    fixed: vendor fix RHSA-2024:2962
  • Red Hat Enterprise Linux AppStream (v. 9) qemu-img 9.0.0-10.el9_5.3, qemu-kvm 9.0.0-10.el9_5.3, qemu-kvm-core 9.0.0-10.el9_5.3, qemu-kvm-tools 9.0.0-10.el9_5.3, qemu-pr-helper 9.0.0-10.el9_5.3, qemu-kvm-common 9.0.0-10.el9_5.3, +13 more
    fixed: vendor fix RHSA-2025:4492
  • Red Hat Enterprise Linux CRB (v. 8) libnbd 1.6.0-5.module+el8.9.0+18724+20190c23, netcf 0.2.8-12.module+el8.9.0+18724+20190c23, hivex 1.3.18-23.module+el8.9.0+18724+20190c23, nbdfuse 1.6.0-5.module+el8.9.0+18724+20190c23, seabios 1.16.0-4.module+el8.9.0+19570+14a90618, SLOF 20210217-2.module+el8.10.0+20141+6faa2812, +38 more
    fixed: vendor fix RHSA-2024:2962

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
17 mo ago

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.9 CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
NVD 3.1 5.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

Affected products

  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8 Advanced Virtualization

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.