CVE-2023-6683

Qemu: vnc: null pointer dereference in qemu_clipboard_request()

MEDIUM
6.5
CVSS Score
Published: January 12, 2024 at 07:01 PM UTC
Updated: June 17, 2026 at 06:51 AM UTC
2 products affected across 2 vendorsEnterprise LinuxQEMU

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Severity
MEDIUM6.5
Exploit prediction
EPSS 1%
SSVC
No known exploit

Description

A flaw was found in the QEMU built-in VNC server while processing ClientCutText messages. The qemu_clipboard_request() function can be reached before vnc_server_cut_text_caps() was called and had the chance to initialize the clipboard peer, leading to a NULL pointer dereference. This could allow a malicious authenticated VNC client to crash QEMU and trigger a denial of service.

Affected

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

6.1.0 ≤ v < 8.2.2
Affected range stops below 8.2.2, so it looks safe — our inference, not a vendor statement
Vendor states this is fixed in 17:8.2.0-11.el9_4 (unaffected)
Vendor states this is fixed in 6 (unaffected)
Vendor states this is fixed in 7 (unaffected)
Vendor states this is fixed in 8100020240314161907.e155f54d (unaffected)

Remediation

No guide yet

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

References (5)

Vendor Advisoryx_refsource_REDHATThird Party Advisory
https://access.redhat.com/errata/RHSA-2024:2135
Vendor Advisoryx_refsource_REDHATThird Party Advisory
https://access.redhat.com/errata/RHSA-2024:2962
VDB Entryx_refsource_REDHATThird Party Advisory
https://access.redhat.com/security/cve/CVE-2023-6683
Third Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
https://security.netapp.com/advisory/ntap-20240223-0001/

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

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

CVSS

6.5MEDIUMredhat
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-476

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