{"id":"GHSA-xrr9-rh8p-433v","summary":"Request smuggling is possible when both chunked TE and content length specified","details":"### Impact\nRequest smuggling is possible when running behind a proxy that doesn't handle Content-Length and Transfer-Encoding properly or doesn't handle alone \\n as a headers separator.\n\n### Patches\nhttps://github.com/ktorio/ktor/pull/1547\n\n### Workarounds\nNone except migrating to a better proxy.\n\n### References\nhttps://portswigger.net/web-security/request-smuggling\nhttps://tools.ietf.org/html/rfc7230#section-9.5","aliases":["CVE-2020-5207"],"modified":"2026-07-08T05:59:54.373628390Z","published":"2020-01-27T19:28:40Z","database_specific":{"cwe_ids":["CWE-444"],"severity":"LOW","github_reviewed":true,"github_reviewed_at":"2020-01-27T19:28:00Z","nvd_published_at":null},"references":[{"type":"WEB","url":"https://github.com/ktorio/ktor/security/advisories/GHSA-xrr9-rh8p-433v"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-5207"},{"type":"WEB","url":"https://github.com/ktorio/ktor/pull/1547"}],"affected":[{"package":{"name":"io.ktor:ktor-client-cio","ecosystem":"Maven","purl":"pkg:maven/io.ktor/ktor-client-cio"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.0"}]}],"versions":["1.0.0","1.0.0-rc","1.0.1","1.1.0","1.1.1","1.1.2","1.1.3","1.1.4","1.1.5","1.2.0","1.2.0-rc","1.2.0-rc2","1.2.1","1.2.2","1.2.3","1.2.3-rc","1.2.4","1.2.5","1.2.6","1.3.0-rc","1.3.0-rc2"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2020/01/GHSA-xrr9-rh8p-433v/GHSA-xrr9-rh8p-433v.json"}},{"package":{"name":"io.ktor:ktor-server-cio","ecosystem":"Maven","purl":"pkg:maven/io.ktor/ktor-server-cio"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.0"}]}],"versions":["1.0.0","1.0.0-rc","1.0.1","1.1.0","1.1.1","1.1.2","1.1.3","1.1.4","1.2.0","1.2.0-rc","1.2.0-rc2","1.2.1","1.2.2","1.2.3","1.2.3-rc","1.2.4","1.2.5","1.2.6","1.3.0-rc","1.3.0-rc2"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2020/01/GHSA-xrr9-rh8p-433v/GHSA-xrr9-rh8p-433v.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"}]}