{"id":"CVE-2024-45614","published":"2024-09-19T22:42:33Z","modified":"2025-11-03T22:15:51Z","title":"Header normalization allows for client to clobber proxy set headers in Puma","vendor":"puma","product":"puma","tier":"tail","description":{"text":"Puma is a Ruby/Rack web server built for parallelism. In affected versions clients could clobber values set by intermediate proxies (such as X-Forwarded-For) by providing a underscore version of the same header (X-Forwarded_For). Any users relying on proxy set variables is affected. v6.4.3/v5.6.9 now discards any headers using underscores if the non-underscore version also exists. Effectively, allowing the proxy defined headers to always win. Users are advised to upgrade. Nginx has a underscores_in_headers configuration variable to discard these headers at the proxy level as a mitigation. Any users that are implicitly trusting the proxy defined headers for security should immediately cease doing so until upgraded to the fixed versions.","provenance":"source","from":"CVE.org"},"cvss":{"score":5.4,"severity":"MEDIUM","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","provenance":"source","from":"CVE.org CNA"},"epss":{"score":0.0064,"percentile":0.5064,"provenance":"source"},"cwes":[{"id":"CWE-639","name":"Authorization Bypass Through User-Controlled Key"}],"references":[{"url":"https://github.com/puma/puma/security/advisories/GHSA-9hf4-67fc-4vf4","tags":["x_refsource_CONFIRM"]},{"url":"https://nginx.org/en/docs/http/ngx_http_core_module.html#underscores_in_headers","tags":["x_refsource_MISC"]},{"url":"https://lists.debian.org/debian-lts-announce/2024/11/msg00004.html","tags":[]}],"priority":{"score":18.9,"factors":[{"name":"EPSS percentile","points":10.13},{"name":"Public exploit code","points":5.0},{"name":"CVSS severity","points":3.78}]},"exploitSources":{"pocGithub":{"count":1,"skipped":0,"earliest":"2024-09-28","earliestUrl":"https://github.com/ooooooo-q/puma_header_normalization-CVE-2024-45614","repos":[{"name":"ooooooo-q/puma_header_normalization-CVE-2024-45614","url":"https://github.com/ooooooo-q/puma_header_normalization-CVE-2024-45614","stars":0,"created":"2024-09-28"}]},"first":{"date":"2024-09-28","source":"PoC-in-GitHub","url":"https://github.com/ooooooo-q/puma_header_normalization-CVE-2024-45614"},"provenance":"source"},"vendorSlug":"puma","affectedVersions":[{"vendor":"puma","product":"puma","versions":[">= 6.0.0, < 6.4.3","< 5.6.9"]}],"affected":[{"ecosystem":"RubyGems","package":"puma","vulnerableRanges":["<5.6.9",">=6.0.0, <6.4.3"],"patched":["5.6.9","6.4.3"],"from":["GHSA-9hf4-67fc-4vf4"],"provenance":"source"}],"euvd":{"id":"EUVD-2024-2761","exploited":false,"provenance":"source"},"lineage":{"familyId":"fam-puma-cve-2022-23633","parents":[{"from":"CVE-2022-23634","to":"CVE-2024-45614","relation":"related","confidence":"medium","kind":"lineage","evidence":[{"kind":"same-code","provenance":"machine","files":["lib/puma/request.rb"],"commits":["https://github.com/puma/puma/commit/b70f451fe8abc0cff192c065d549778452e155bb","https://github.com/puma/puma/commit/cac3fd18cf29ed43719ff5d52d9cfec215f0a043","https://github.com/puma/puma/commit/f196b23be24712fb8fb16051cc124798cc84f70e"],"basis":"rarely changed file"}]}],"packageHistory":[{"cve":"CVE-2022-24790","published":"2022-03-30","fixed":"5.6.4","kev":false},{"cve":"CVE-2023-40175","published":"2023-08-18","fixed":"6.3.1","kev":false},{"cve":"CVE-2024-21647","published":"2024-01-08","fixed":"6.4.2","kev":false,"link":{"from":"CVE-2024-21647","to":"CVE-2024-45614","relation":"successor","confidence":"low","kind":"sequence","evidence":[{"kind":"version-step","provenance":"source","package":"RubyGems:puma","fromFixed":"5.6.8","toFixed":"5.6.9","daysApart":255},{"kind":"version-step","provenance":"source","package":"RubyGems:puma","fromFixed":"6.4.2","toFixed":"6.4.3","daysApart":255}]}},{"cve":"CVE-2024-45614","published":"2024-09-19","fixed":"6.4.3","kev":false},{"cve":"CVE-2026-47736","published":"2026-07-14","fixed":"8.0.2","kev":false},{"cve":"CVE-2026-47737","published":"2026-07-14","fixed":"8.0.2","kev":false}],"package":"RubyGems:puma"}}