{"id":"BIT-apache-2021-33193","summary":"Request splitting via HTTP/2 method injection and mod_proxy","details":"A crafted method sent through HTTP/2 will bypass validation and be forwarded by mod_proxy, which can lead to request splitting or cache poisoning. This issue affects Apache HTTP Server 2.4.17 to 2.4.48.","aliases":["CVE-2021-33193"],"modified":"2025-05-20T10:02:07.006Z","published":"2024-03-06T10:55:40.870Z","database_specific":{"severity":"High","cpes":["cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*"]},"references":[{"type":"WEB","url":"https://github.com/apache/httpd/commit/ecebcc035ccd8d0e2984fe41420d9e944f456b3c.patch"},{"type":"WEB","url":"https://lists.apache.org/thread.html/re4162adc051c1a0a79e7a24093f3776373e8733abaff57253fef341d%40%3Ccvs.httpd.apache.org%3E"},{"type":"WEB","url":"https://lists.apache.org/thread.html/ree7519d71415ecdd170ff1889cab552d71758d2ba2904a17ded21a70%40%3Ccvs.httpd.apache.org%3E"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2023/03/msg00002.html"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DSM6UWQICBJ2TU727RENU3HBKEAFLT6T/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EUVJVRJRBW5QVX4OY3NOHZDQ3B3YOTSG/"},{"type":"WEB","url":"https://portswigger.net/research/http2"},{"type":"WEB","url":"https://security.gentoo.org/glsa/202208-20"},{"type":"WEB","url":"https://security.netapp.com/advisory/ntap-20210917-0004/"},{"type":"WEB","url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQ"},{"type":"WEB","url":"https://www.oracle.com/security-alerts/cpuapr2022.html"},{"type":"WEB","url":"https://www.oracle.com/security-alerts/cpujan2022.html"},{"type":"WEB","url":"https://www.tenable.com/security/tns-2021-17"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-33193"}],"affected":[{"package":{"name":"apache","ecosystem":"Bitnami","purl":"pkg:bitnami/apache"},"ranges":[{"type":"SEMVER","events":[{"introduced":"2.4.17"},{"fixed":"2.4.49"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/apache/BIT-apache-2021-33193.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}],"schema_version":"1.7.3"}