CVE-2023-6683 MEDIUM

CVE-2023-6683: Qemu: vnc: null pointer dereference in qemu_clipboard_request()

Vendor Red Hat
Product Red Hat Enterprise Linux 6
Weakness CWE-476
Published January 12, 2024
Last update February 25, 2026

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

January 12, 2024 CVE published
February 25, 2026 Record updated