{"api_version":"1","generated_at":"2026-04-30T16:05:40+00:00","cve":"CVE-2021-41267","urls":{"html":"https://cve.report/CVE-2021-41267","api":"https://cve.report/api/cve/CVE-2021-41267.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2021-41267","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-41267"},"summary":{"title":"CVE-2021-41267","description":"Symfony/Http-Kernel is the HTTP kernel component for Symfony, a PHP framework for web and console applications and a set of reusable PHP components. Headers that are not part of the \"trusted_headers\" allowed list are ignored and protect users from \"Cache poisoning\" attacks. In Symfony 5.2, maintainers added support for the `X-Forwarded-Prefix` headers, but this header was accessible in SubRequest, even if it was not part of the \"trusted_headers\" allowed list. An attacker could leverage this opportunity to forge requests containing a `X-Forwarded-Prefix` header, leading to a web cache poisoning issue. 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Versions 5.3.12 and later have a patch to ensure that the `X-Forwarded-Prefix` header is not forwarded to subrequests when it is not trusted."}]},"impact":{"cvss":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling')"}]}]},"references":{"reference_data":[{"name":"https://github.com/symfony/symfony/pull/44243","refsource":"MISC","url":"https://github.com/symfony/symfony/pull/44243"},{"name":"https://github.com/symfony/symfony/releases/tag/v5.3.12","refsource":"MISC","url":"https://github.com/symfony/symfony/releases/tag/v5.3.12"},{"name":"https://github.com/symfony/symfony/security/advisories/GHSA-q3j3-w37x-hq2q","refsource":"CONFIRM","url":"https://github.com/symfony/symfony/security/advisories/GHSA-q3j3-w37x-hq2q"},{"name":"https://github.com/symfony/symfony/commit/95dcf51682029e89450aee86267e3d553aa7c487","refsource":"MISC","url":"https://github.com/symfony/symfony/commit/95dcf51682029e89450aee86267e3d553aa7c487"}]},"source":{"advisory":"GHSA-q3j3-w37x-hq2q","discovery":"UNKNOWN"}},"nvd":{"publishedDate":"2021-11-24 19:15:00","lastModifiedDate":"2021-11-30 18:52:00","problem_types":["CWE-444"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM"},"exploitabilityScore":2.8,"impactScore":3.6},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:N/AC:M/Au:N/C:N/I:P/A:N","accessVector":"NETWORK","accessComplexity":"MEDIUM","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"PARTIAL","availabilityImpact":"NONE","baseScore":4.3},"severity":"MEDIUM","exploitabilityScore":8.6,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":true}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*","versionStartIncluding":"5.2.0","versionEndExcluding":"5.3.12","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2021","CveId":"41267","Ordinal":"216874","Title":"CVE-2021-41267","CVE":"CVE-2021-41267","Year":"2021"},"notes":[{"CveYear":"2021","CveId":"41267","Ordinal":"1","NoteData":"Symfony/Http-Kernel is the HTTP kernel component for Symfony, a PHP framework for web and console applications and a set of reusable PHP components. Headers that are not part of the \"trusted_headers\" allowed list are ignored and protect users from \"Cache poisoning\" attacks. In Symfony 5.2, maintainers added support for the `X-Forwarded-Prefix` headers, but this header was accessible in SubRequest, even if it was not part of the \"trusted_headers\" allowed list. An attacker could leverage this opportunity to forge requests containing a `X-Forwarded-Prefix` header, leading to a web cache poisoning issue. Versions 5.3.12 and later have a patch to ensure that the `X-Forwarded-Prefix` header is not forwarded to subrequests when it is not trusted.","Type":"Description","Title":null},{"CveYear":"2021","CveId":"41267","Ordinal":"2","NoteData":"2021-11-24","Type":"Other","Title":"Published"},{"CveYear":"2021","CveId":"41267","Ordinal":"3","NoteData":"2021-11-24","Type":"Other","Title":"Modified"}]}}}