{"id":"UBUNTU-CVE-2021-21419","details":"Eventlet is a concurrent networking library for Python. A websocket peer may exhaust memory on Eventlet side by sending very large websocket frames. Malicious peer may exhaust memory on Eventlet side by sending highly compressed data frame. A patch in version 0.31.0 restricts websocket frame to reasonable limits. As a workaround, restricting memory usage via OS limits would help against overall machine exhaustion, but there is no workaround to protect Eventlet process.","modified":"2026-02-04T04:26:19.535349Z","published":"2021-05-07T15:15:00Z","related":["USN-4956-1"],"upstream":["CVE-2021-21419"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-21419"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-4956-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-21419"}],"affected":[{"package":{"name":"python-eventlet","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/python-eventlet@0.25.1-2ubuntu1.1?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.25.1-2ubuntu1.1"}]}],"versions":["0.25.0-0ubuntu1","0.25.1-2build1","0.25.1-2ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_version":"0.25.1-2ubuntu1.1","binary_name":"python3-eventlet"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21419.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},{"type":"Ubuntu","score":"medium"}]}