🛡️ CVE-2021-41267
🟡 CVSS 5.0 — Medium ✅ No Known Exploit OSV
5.0
CVSS Score
0 Low4 Medium7 High9 Critical10

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. 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.

Details

Severity MEDIUM
CVSS Score 5.0
CVSS Vector N/A
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2024-03-06
Updated 2026-06-08
Modified 2024-03-06
Fix URL N/A

Affected Packages

Software From version Fixed in
symfony — —
symfony/http-kernel 5.2.0 5.3.12
symfony/symfony 5.2.0 5.3.12

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