CVE-2023-6693

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

MEDIUM
5.3
CVSS Score
Published: January 2, 2024 at 09:15 AM UTC
Updated: June 17, 2026 at 06:51 AM UTC
4 products affected across 3 vendorsFedoraEnterprise LinuxQEMU

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 8.2.1
Affected range stops below 8.2.1, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 17:9.0.0-10.el9_5.3 (unaffected)
Vendor states this is fixed in 8100020240314161907.e155f54d (unaffected)
Vendor states this is fixed in 6 (unknown)
Vendor states this is fixed in 7 (unknown)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
LOW
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-121CWE-787

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