What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-01-12 · updated 2026-06-17
• Weakness: CWE-476

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 products

• QEMU: from 6.1.0 before 8.2.2 — fixed in 8.2.2
• Red Hat Enterprise Linux: 8.0, 9.0

How to fix

Upgrade to a fixed version: QEMU 8.2.2. Check the vendor advisory for mitigations.

References

• https://access.redhat.com/errata/RHSA-2024:2135
• https://access.redhat.com/errata/RHSA-2024:2962
• https://access.redhat.com/security/cve/CVE-2023-6683
• https://bugzilla.redhat.com/show_bug.cgi?id=2254825
• https://access.redhat.com/errata/RHSA-2024:2135
• https://access.redhat.com/errata/RHSA-2024:2962
• https://access.redhat.com/security/cve/CVE-2023-6683
• https://bugzilla.redhat.com/show_bug.cgi?id=2254825
• https://security.netapp.com/advisory/ntap-20240223-0001/

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