{"id":"UBUNTU-CVE-2023-3354","details":"A flaw was found in the QEMU built-in VNC server. When a client connects to the VNC server, QEMU checks whether the current number of connections crosses a certain threshold and if so, cleans up the previous connection. If the previous connection happens to be in the handshake phase and fails, QEMU cleans up the connection again, resulting in a NULL pointer dereference issue. This could allow a remote unauthenticated client to cause a denial of service.","modified":"2026-06-09T21:29:23.148997237Z","published":"2023-07-11T17:15:00Z","related":["USN-6567-1","USN-8412-1"],"upstream":["CVE-2023-3354"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2023-3354"},{"type":"REPORT","url":"https://lists.nongnu.org/archive/html/qemu-devel/2023-07/msg02668.html"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-6567-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2023-3354"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8412-1"}],"affected":[{"package":{"name":"qemu","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/qemu?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:2.11+dfsg-1ubuntu7.42+esm5"}]}],"versions":["1:2.10+dfsg-0ubuntu3","1:2.10+dfsg-0ubuntu4","1:2.10+dfsg-0ubuntu5","1:2.11+dfsg-1ubuntu1","1:2.11+dfsg-1ubuntu2","1:2.11+dfsg-1ubuntu4","1:2.11+dfsg-1ubuntu5","1:2.11+dfsg-1ubuntu6","1:2.11+dfsg-1ubuntu7","1:2.11+dfsg-1ubuntu7.1","1:2.11+dfsg-1ubuntu7.2","1:2.11+dfsg-1ubuntu7.3","1:2.11+dfsg-1ubuntu7.4","1:2.11+dfsg-1ubuntu7.5","1:2.11+dfsg-1ubuntu7.6","1:2.11+dfsg-1ubuntu7.7","1:2.11+dfsg-1ubuntu7.8","1:2.11+dfsg-1ubuntu7.9","1:2.11+dfsg-1ubuntu7.10","1:2.11+dfsg-1ubuntu7.12","1:2.11+dfsg-1ubuntu7.13","1:2.11+dfsg-1ubuntu7.14","1:2.11+dfsg-1ubuntu7.15","1:2.11+dfsg-1ubuntu7.17","1:2.11+dfsg-1ubuntu7.18","1:2.11+dfsg-1ubuntu7.19","1:2.11+dfsg-1ubuntu7.20","1:2.11+dfsg-1ubuntu7.21","1:2.11+dfsg-1ubuntu7.22","1:2.11+dfsg-1ubuntu7.23","1:2.11+dfsg-1ubuntu7.25","1:2.11+dfsg-1ubuntu7.26","1:2.11+dfsg-1ubuntu7.27","1:2.11+dfsg-1ubuntu7.28","1:2.11+dfsg-1ubuntu7.29","1:2.11+dfsg-1ubuntu7.31","1:2.11+dfsg-1ubuntu7.32","1:2.11+dfsg-1ubuntu7.33","1:2.11+dfsg-1ubuntu7.34","1:2.11+dfsg-1ubuntu7.35","1:2.11+dfsg-1ubuntu7.36","1:2.11+dfsg-1ubuntu7.37","1:2.11+dfsg-1ubuntu7.38","1:2.11+dfsg-1ubuntu7.39","1:2.11+dfsg-1ubuntu7.40","1:2.11+dfsg-1ubuntu7.41","1:2.11+dfsg-1ubuntu7.42","1:2.11+dfsg-1ubuntu7.42+esm1","1:2.11+dfsg-1ubuntu7.42+esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"qemu","binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5"},{"binary_name":"qemu-block-extra","binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5"},{"binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5","binary_name":"qemu-guest-agent"},{"binary_name":"qemu-kvm","binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5"},{"binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5","binary_name":"qemu-system"},{"binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5","binary_name":"qemu-system-arm"},{"binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5","binary_name":"qemu-system-common"},{"binary_name":"qemu-system-mips","binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5"},{"binary_name":"qemu-system-misc","binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5"},{"binary_name":"qemu-system-ppc","binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5"},{"binary_name":"qemu-system-s390x","binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5"},{"binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5","binary_name":"qemu-system-sparc"},{"binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5","binary_name":"qemu-system-x86"},{"binary_name":"qemu-user","binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5"},{"binary_name":"qemu-user-binfmt","binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5"},{"binary_name":"qemu-user-static","binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5"},{"binary_version":"1:2.11+dfsg-1ubuntu7.42+esm5","binary_name":"qemu-utils"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","priority_reason":"Limited to a denial of service in the VNC server component."},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-3354.json"}},{"package":{"name":"qemu","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/qemu?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:4.2-3ubuntu6.28"}]}],"versions":["1:4.0+dfsg-0ubuntu9","1:4.0+dfsg-0ubuntu10","1:4.2-1ubuntu1","1:4.2-1ubuntu2","1:4.2-3ubuntu1","1:4.2-3ubuntu2","1:4.2-3ubuntu3","1:4.2-3ubuntu4","1:4.2-3ubuntu5","1:4.2-3ubuntu6","1:4.2-3ubuntu6.1","1:4.2-3ubuntu6.2","1:4.2-3ubuntu6.3","1:4.2-3ubuntu6.4","1:4.2-3ubuntu6.5","1:4.2-3ubuntu6.6","1:4.2-3ubuntu6.7","1:4.2-3ubuntu6.8","1:4.2-3ubuntu6.9","1:4.2-3ubuntu6.10","1:4.2-3ubuntu6.11","1:4.2-3ubuntu6.12","1:4.2-3ubuntu6.14","1:4.2-3ubuntu6.15","1:4.2-3ubuntu6.16","1:4.2-3ubuntu6.17","1:4.2-3ubuntu6.18","1:4.2-3ubuntu6.19","1:4.2-3ubuntu6.21","1:4.2-3ubuntu6.23","1:4.2-3ubuntu6.24","1:4.2-3ubuntu6.25","1:4.2-3ubuntu6.26","1:4.2-3ubuntu6.27"],"ecosystem_specific":{"availability":"No subscription required","priority_reason":"Limited to a denial of service in the VNC server component.","binaries":[{"binary_version":"1:4.2-3ubuntu6.28","binary_name":"qemu"},{"binary_version":"1:4.2-3ubuntu6.28","binary_name":"qemu-block-extra"},{"binary_name":"qemu-guest-agent","binary_version":"1:4.2-3ubuntu6.28"},{"binary_name":"qemu-kvm","binary_version":"1:4.2-3ubuntu6.28"},{"binary_name":"qemu-system","binary_version":"1:4.2-3ubuntu6.28"},{"binary_name":"qemu-system-arm","binary_version":"1:4.2-3ubuntu6.28"},{"binary_name":"qemu-system-common","binary_version":"1:4.2-3ubuntu6.28"},{"binary_name":"qemu-system-data","binary_version":"1:4.2-3ubuntu6.28"},{"binary_name":"qemu-system-gui","binary_version":"1:4.2-3ubuntu6.28"},{"binary_name":"qemu-system-mips","binary_version":"1:4.2-3ubuntu6.28"},{"binary_name":"qemu-system-misc","binary_version":"1:4.2-3ubuntu6.28"},{"binary_version":"1:4.2-3ubuntu6.28","binary_name":"qemu-system-ppc"},{"binary_version":"1:4.2-3ubuntu6.28","binary_name":"qemu-system-s390x"},{"binary_name":"qemu-system-sparc","binary_version":"1:4.2-3ubuntu6.28"},{"binary_name":"qemu-system-x86","binary_version":"1:4.2-3ubuntu6.28"},{"binary_name":"qemu-system-x86-microvm","binary_version":"1:4.2-3ubuntu6.28"},{"binary_version":"1:4.2-3ubuntu6.28","binary_name":"qemu-system-x86-xen"},{"binary_name":"qemu-user","binary_version":"1:4.2-3ubuntu6.28"},{"binary_version":"1:4.2-3ubuntu6.28","binary_name":"qemu-user-binfmt"},{"binary_name":"qemu-user-static","binary_version":"1:4.2-3ubuntu6.28"},{"binary_version":"1:4.2-3ubuntu6.28","binary_name":"qemu-utils"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-3354.json"}},{"package":{"name":"qemu","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/qemu?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:6.2+dfsg-2ubuntu6.16"}]}],"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"],"ecosystem_specific":{"priority_reason":"Limited to a denial of service in the VNC server component.","binaries":[{"binary_name":"qemu","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_name":"qemu-block-extra","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_name":"qemu-guest-agent","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_version":"1:6.2+dfsg-2ubuntu6.16","binary_name":"qemu-system"},{"binary_name":"qemu-system-arm","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_name":"qemu-system-common","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_version":"1:6.2+dfsg-2ubuntu6.16","binary_name":"qemu-system-data"},{"binary_name":"qemu-system-gui","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_name":"qemu-system-mips","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_name":"qemu-system-misc","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_name":"qemu-system-ppc","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_name":"qemu-system-s390x","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_name":"qemu-system-sparc","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_name":"qemu-system-x86","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_name":"qemu-system-x86-microvm","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_version":"1:6.2+dfsg-2ubuntu6.16","binary_name":"qemu-system-x86-xen"},{"binary_version":"1:6.2+dfsg-2ubuntu6.16","binary_name":"qemu-user"},{"binary_name":"qemu-user-binfmt","binary_version":"1:6.2+dfsg-2ubuntu6.16"},{"binary_version":"1:6.2+dfsg-2ubuntu6.16","binary_name":"qemu-user-static"},{"binary_name":"qemu-utils","binary_version":"1:6.2+dfsg-2ubuntu6.16"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-3354.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"low"}]}