CVE-2023-6693

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

publishedCWE-121

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.

Technical severity4.9 mediumCVSS 3.1 · CNA: redhat

Published2024-01-02Source updated 2026-11-05

Collected2026-11-052 attributed sources

Fixes and workarounds

Workaround

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Source: CNA: redhat

Affected products and versions

Affected products, source version ranges and reporting authorities
Product	Versions	Authority
Red Hat Enterprise Linux 8 Red Hat `virt-devel:rhel` https://access.redhat.com/downloads/content/package-browser/	≥ 8100020240314161907.e155f54d; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 8 Red Hat `virt:rhel` https://access.redhat.com/downloads/content/package-browser/	≥ 8100020240314161907.e155f54d; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 9 Red Hat `qemu-kvm` https://access.redhat.com/downloads/content/package-browser/	≥ 17:9.0.0-10.el9_5.3; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 6 Red Hat `qemu-kvm` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unknown	CNA: redhat
Red Hat Enterprise Linux 7 Red Hat `qemu-kvm` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unknown	CNA: redhat
Red Hat Enterprise Linux 7 Red Hat `qemu-kvm-ma` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unknown	CNA: redhat
Red Hat Enterprise Linux 8 Advanced Virtualization Red Hat `virt:av/qemu-kvm` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: affected	CNA: redhat

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / score	Vector	Authority
3.1 / 4.9 medium	`CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L`	CNA: redhat

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

https://access.redhat.com/errata/RHSA-2024:2962CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2025:4492CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2023-6693CNA: redhat · vdb-entry, x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2254580CNA: redhat · issue-tracking, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2024:2962ADP: CVE · vendor-advisory, x_refsource_REDHAT, x_transferred
https://access.redhat.com/security/cve/CVE-2023-6693ADP: CVE · vdb-entry, x_refsource_REDHAT, x_transferred
https://bugzilla.redhat.com/show_bug.cgi?id=2254580ADP: CVE · issue-tracking, x_refsource_REDHAT, x_transferred
https://lists.fedoraproject.org/archives/list/[email protected]/message/OYGUN5HVOXESW7MSNM44E4AE2VNXQB6Y/ADP: CVE · x_transferred
https://security.netapp.com/advisory/ntap-20240208-0004/ADP: CVE · x_transferred
https://lists.debian.org/debian-lts-announce/2025/04/msg00042.htmlADP: CVE

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