{"id":"UBUNTU-CVE-2021-21409","details":"Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In Netty (io.netty:netty-codec-http2) before version 4.1.61.Final there is a vulnerability that enables request smuggling. The content-length header is not correctly validated if the request only uses a single Http2HeaderFrame with the endStream set to to true. This could lead to request smuggling if the request is proxied to a remote peer and translated to HTTP/1.1. This is a followup of GHSA-wm47-8v5p-wjpj/CVE-2021-21295 which did miss to fix this one case. This was fixed as part of 4.1.61.Final.","modified":"2026-06-08T18:49:20.962920336Z","published":"2021-03-30T15:15:00Z","related":["USN-6049-1"],"upstream":["CVE-2021-21409"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-21409"},{"type":"REPORT","url":"https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21295"},{"type":"REPORT","url":"https://github.com/netty/netty/commit/b0fa4d5aab4215f3c22ce6123dd8dd5f38dc0432"},{"type":"REPORT","url":"https://github.com/netty/netty/security/advisories/GHSA-f256-j965-7f32"},{"type":"REPORT","url":"https://github.com/netty/netty/security/advisories/GHSA-wm47-8v5p-wjpj"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-6049-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-21409"}],"affected":[{"package":{"name":"netty","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/netty?arch=source&distro=esm-infra-legacy%2Ftrusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:3.2.6.Final-2","1:3.2.6.Final-2+deb8u2build0.14.04.1~esm1","1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libnetty-java","binary_version":"1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21409.json"}},{"package":{"name":"netty","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:4.0.34-1ubuntu0.1~esm1"}]}],"versions":["1:3.2.6.Final-2","1:4.0.32-1","1:4.0.33-1","1:4.0.34-1"],"ecosystem_specific":{"binaries":[{"binary_version":"1:4.0.34-1ubuntu0.1~esm1","binary_name":"libnetty-java"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21409.json"}},{"package":{"name":"netty","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:4.1.7-4ubuntu0.1+esm2"}]}],"versions":["1:4.1.7-4","1:4.1.7-4ubuntu0.1~esm1","1:4.1.7-4ubuntu0.1","1:4.1.7-4ubuntu0.1+esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"1:4.1.7-4ubuntu0.1+esm2","binary_name":"libnetty-java"}],"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21409.json"}},{"package":{"name":"netty","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/netty?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:4.1.45-1ubuntu0.1~esm1"}]}],"versions":["1:4.1.33-1","1:4.1.33-2","1:4.1.33-3","1:4.1.45-1"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro: https://ubuntu.com/pro","binaries":[{"binary_version":"1:4.1.45-1ubuntu0.1~esm1","binary_name":"libnetty-java"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21409.json"}},{"package":{"name":"netty","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/netty?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:4.1.48-4+deb11u1build0.22.04.1"}]}],"versions":["1:4.1.48-4"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_name":"libnetty-java","binary_version":"1:4.1.48-4+deb11u1build0.22.04.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-21409.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N"},{"type":"Ubuntu","score":"medium"}]}