{"id":"UBUNTU-CVE-2018-21035","details":"In Qt through 5.14.1, the WebSocket implementation accepts up to 2GB for frames and 2GB for messages. Smaller limits cannot be configured. This makes it easier for attackers to cause a denial of service (memory consumption).","modified":"2025-10-24T04:47:19Z","published":"2020-02-28T21:15:00Z","upstream":["CVE-2018-21035"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2018-21035"},{"type":"REPORT","url":"https://codereview.qt-project.org/c/qt/qtwebsockets/+/284735"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2018-21035"}],"affected":[{"package":{"name":"qtwebsockets-opensource-src","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/qtwebsockets-opensource-src@5.5.1-4build1?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.4.2-2build1","5.5.1-4build1"],"ecosystem_specific":{"binaries":[{"binary_version":"5.5.1-4build1","binary_name":"libqt5websockets5"},{"binary_version":"5.5.1-4build1","binary_name":"libqt5websockets5-dev"},{"binary_version":"5.5.1-4build1","binary_name":"qml-module-qt-websockets"},{"binary_version":"5.5.1-4build1","binary_name":"qml-module-qtwebsockets"},{"binary_version":"5.5.1-4build1","binary_name":"qtwebsockets5-doc-html"},{"binary_version":"5.5.1-4build1","binary_name":"qtwebsockets5-examples"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-21035.json"}},{"package":{"name":"qtwebsockets-opensource-src","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/qtwebsockets-opensource-src@5.9.5-0ubuntu1?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.9.1-3","5.9.2-3build1","5.9.3-0ubuntu1","5.9.4-0ubuntu1","5.9.5-0ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_version":"5.9.5-0ubuntu1","binary_name":"libqt5websockets5"},{"binary_version":"5.9.5-0ubuntu1","binary_name":"libqt5websockets5-dev"},{"binary_version":"5.9.5-0ubuntu1","binary_name":"qml-module-qt-websockets"},{"binary_version":"5.9.5-0ubuntu1","binary_name":"qml-module-qtwebsockets"},{"binary_version":"5.9.5-0ubuntu1","binary_name":"qtwebsockets5-doc-html"},{"binary_version":"5.9.5-0ubuntu1","binary_name":"qtwebsockets5-examples"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-21035.json"}},{"package":{"name":"qtwebsockets-opensource-src","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/qtwebsockets-opensource-src@5.12.8-0ubuntu1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.12.4-1","5.12.5-2","5.12.5-2build1","5.12.8-0ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_version":"5.12.8-0ubuntu1","binary_name":"libqt5websockets5"},{"binary_version":"5.12.8-0ubuntu1","binary_name":"libqt5websockets5-dev"},{"binary_version":"5.12.8-0ubuntu1","binary_name":"qml-module-qt-websockets"},{"binary_version":"5.12.8-0ubuntu1","binary_name":"qml-module-qtwebsockets"},{"binary_version":"5.12.8-0ubuntu1","binary_name":"qtwebsockets5-doc-html"},{"binary_version":"5.12.8-0ubuntu1","binary_name":"qtwebsockets5-examples"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-21035.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/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"}]}