{"id":"CVE-2024-45614","state":"PUBLISHED","title":"Header normalization allows for client to clobber proxy set headers in Puma","description":"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.","publishedAt":"2024-09-19T22:42:33.974Z","updatedAt":"2025-11-03T22:15:51.621Z","severity":{"score":5.4,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["puma puma"],"affected":[{"vendor":"puma","product":"puma","versions":[{"version":">= 6.0.0, < 6.4.3","status":"affected"},{"version":"< 5.6.9","status":"affected"}]}],"references":["https://github.com/puma/puma/security/advisories/GHSA-9hf4-67fc-4vf4","https://nginx.org/en/docs/http/ngx_http_core_module.html#underscores_in_headers","https://lists.debian.org/debian-lts-announce/2024/11/msg00004.html"],"weaknesses":["CWE-639"],"ingestedAt":"2026-10-29T20:07:47.831Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/45xxx/CVE-2024-45614.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-45614","state":"PUBLISHED","datePublished":"2024-09-19T22:42:33.974Z","dateUpdated":"2025-11-03T22:15:51.621Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2024-09-02T16:00:02.425Z"},"containers":{"cna":{"title":"Header normalization allows for client to clobber proxy set headers in Puma","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"puma","product":"puma","versions":[{"version":">= 6.0.0, < 6.4.3","status":"affected"},{"version":"< 5.6.9","status":"affected"}]}],"references":[{"url":"https://github.com/puma/puma/security/advisories/GHSA-9hf4-67fc-4vf4","name":"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","name":"https://nginx.org/en/docs/http/ngx_http_core_module.html#underscores_in_headers","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.4,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-639","lang":"en","description":"CWE-639: Authorization Bypass Through User-Controlled Key","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2024-09-19T22:42:33.974Z"},"source":{"advisory":"GHSA-9hf4-67fc-4vf4","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2024-09-20T13:54:35.745068Z","id":"CVE-2024-45614","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-20T13:54:50.515Z"}},{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2024/11/msg00004.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T22:15:51.621Z"}}]}}}