{"id":"CVE-2021-33037","aliases":["BIT-tomcat-2021-33037","GHSA-4vww-mc66-62m6"],"url":"https://o3.security/vulnerability/CVE-2021-33037","summary":"HTTP Request Smuggling in Apache Tomcat","details":"Apache Tomcat 10.0.0-M1 to 10.0.6, 9.0.0.M1 to 9.0.46 and 8.5.0 to 8.5.66 did not correctly parse the HTTP transfer-encoding request header in some circumstances leading to the possibility to request smuggling when used with a reverse proxy. Specifically: - Tomcat incorrectly ignored the transfer encoding header if the client declared it would only accept an HTTP/1.0 response; - Tomcat honoured the identify encoding; and - Tomcat did not ensure that, if present, the chunked encoding was the final encoding.","published":"2021-07-12T15:15:08.400Z","modified":"2026-08-27T11:46:30.453374017Z","cvss":{"score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat","fixedVersion":"10.0.7"},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat","fixedVersion":"9.0.48"},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat","fixedVersion":"8.5.68"}],"fix":null,"references":[{"type":"WEB","url":"https://lists.apache.org/thread.html/r290aee55b72811fd19e75ac80f6143716c079170c5671b96932ed44b%40%3Ccommits.tomee.apache.org%3E"},{"type":"WEB","url":"https://lists.apache.org/thread.html/r40f921575aee8d7d34e53182f862c45cbb8f3d898c9d4e865c2ec262%40%3Ccommits.tomee.apache.org%3E"},{"type":"WEB","url":"https://lists.apache.org/thread.html/rc6ef52453bb996a98cb45442871a1db56b7c349939e45d829bf9ae37%40%3Ccommits.tomee.apache.org%3E"},{"type":"WEB","url":"https://lists.apache.org/thread.html/rd0dfea39829bc0606c936a16f6fca338127c86c0a1083970b45ac8d2%40%3Ccommits.tomee.apache.org%3E"},{"type":"WEB","url":"https://lists.apache.org/thread.html/re01e7e93154e8bdf78a11a23f9686427bd3d51fc6e12c508645567b7%40%3Ccommits.tomee.apache.org%3E"},{"type":"WEB","url":"https://lists.apache.org/thread.html/rf1b54fd3f52f998ca4829159a88cc4c23d6cef5c6447d00948e75c97%40%3Ccommits.tomee.apache.org%3E"},{"type":"ADVISORY","url":"https://kc.mcafee.com/corporate/index?page=content&id=SB10366"},{"type":"ADVISORY","url":"https://lists.apache.org/thread.html/r612a79269b0d5e5780c62dfd34286a8037232fec0bc6f1a7e60c9381%40%3Cannounce.tomcat.apache.org%3E"},{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2021/08/msg00009.html"},{"type":"ADVISORY","url":"https://security.gentoo.org/glsa/202208-34"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20210827-0007/"},{"type":"ADVISORY","url":"https://www.debian.org/security/2021/dsa-4952"},{"type":"FIX","url":"https://www.oracle.com//security-alerts/cpujul2021.html"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpuapr2022.html"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpujan2022.html"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpuoct2021.html"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-27T11:46:30.453374017Z"}}