{"id":"UBUNTU-CVE-2023-6683","details":"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.","modified":"2026-02-04T03:33:10.733737Z","published":"2024-01-12T19:15:00Z","related":["USN-6954-1"],"upstream":["CVE-2023-6683"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2023-6683"},{"type":"REPORT","url":"https://access.redhat.com/security/cve/CVE-2023-6683"},{"type":"REPORT","url":"https://lists.nongnu.org/archive/html/qemu-devel/2024-01/msg02382.html"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2023-6683"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-6954-1"}],"affected":[{"package":{"name":"qemu","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/qemu@1:6.2+dfsg-2ubuntu6.22?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:6.2+dfsg-2ubuntu6.22"}]}],"versions":["1:6.0+dfsg-2expubuntu1","1:6.0+dfsg-2expubuntu2","1:6.0+dfsg-2expubuntu4","1:6.2+dfsg-2ubuntu5","1:6.2+dfsg-2ubuntu6","1:6.2+dfsg-2ubuntu6.1","1:6.2+dfsg-2ubuntu6.2","1:6.2+dfsg-2ubuntu6.3","1:6.2+dfsg-2ubuntu6.4","1:6.2+dfsg-2ubuntu6.5","1:6.2+dfsg-2ubuntu6.6","1:6.2+dfsg-2ubuntu6.7","1:6.2+dfsg-2ubuntu6.8","1:6.2+dfsg-2ubuntu6.9","1:6.2+dfsg-2ubuntu6.10","1:6.2+dfsg-2ubuntu6.11","1:6.2+dfsg-2ubuntu6.12","1:6.2+dfsg-2ubuntu6.13","1:6.2+dfsg-2ubuntu6.14","1:6.2+dfsg-2ubuntu6.15","1:6.2+dfsg-2ubuntu6.16","1:6.2+dfsg-2ubuntu6.17","1:6.2+dfsg-2ubuntu6.18","1:6.2+dfsg-2ubuntu6.19","1:6.2+dfsg-2ubuntu6.21"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-block-extra"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-guest-agent"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-system"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-system-arm"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-system-common"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-system-data"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-system-gui"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-system-mips"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-system-misc"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-system-ppc"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-system-s390x"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-system-sparc"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-system-x86"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-system-x86-microvm"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-system-x86-xen"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-user"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-user-binfmt"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-user-static"},{"binary_version":"1:6.2+dfsg-2ubuntu6.22","binary_name":"qemu-utils"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-6683.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}