{"id":"GHSA-9p9m-jm8w-94p2","summary":"Improper Handling of Highly Compressed Data (Data Amplification) and Memory Allocation with Excessive Size Value in eventlet","details":"### Impact\nA 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.\n\n### Patches\nVersion 0.31.0 restricts websocket frame to reasonable limits.\n\n### Workarounds\nRestricting memory usage via OS limits would help against overall machine exhaustion. No workaround to protect Eventlet process.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [eventlet](https://github.com/eventlet/eventlet/issues)\n* Contact current maintainers. At 2021-03: temotor@gmail.com or https://t.me/temotor","aliases":["CVE-2021-21419","PYSEC-2021-12"],"modified":"2026-07-08T06:27:42.178135165Z","published":"2021-05-07T15:50:36Z","database_specific":{"nvd_published_at":"2021-05-07T15:15:00Z","severity":"MODERATE","cwe_ids":["CWE-400"],"github_reviewed_at":"2021-05-07T14:31:05Z","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/eventlet/eventlet/security/advisories/GHSA-9p9m-jm8w-94p2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21419"},{"type":"WEB","url":"https://github.com/eventlet/eventlet/commit/1412f5e4125b4313f815778a1acb4d3336efcd07"},{"type":"PACKAGE","url":"https://github.com/eventlet/eventlet"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/eventlet/PYSEC-2021-12.yaml"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2WJFSBPLCNSZNHYQC4QDRDFRTEZRMD2L"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/R5JZP4LZOSP7CUAM3GIRW6PIAWKH5VGB"}],"affected":[{"package":{"name":"eventlet","ecosystem":"PyPI","purl":"pkg:pypi/eventlet"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.10"},{"fixed":"0.31.0"}]}],"versions":["0.10.0","0.11.0","0.12.1","0.13.0","0.14.0","0.15.2","0.16.1","0.17.4","0.18.2","0.18.3","0.18.4","0.19.0","0.20.0","0.20.1","0.21.0","0.22.0","0.22.1","0.23.0","0.24.0","0.24.1","0.25.0","0.25.1","0.25.2","0.26.0","0.26.1","0.27.0","0.28.0","0.28.1","0.29.0","0.29.1","0.30.0","0.30.1","0.30.2","0.30.3"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/05/GHSA-9p9m-jm8w-94p2/GHSA-9p9m-jm8w-94p2.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:L"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"}]}