CVE-2021-41267
Webcache Poisoning in Symfony
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.
CVSS Vector Breakdown
AV:NAttack VectorAC:LAttack ComplexityPR:NPrivileges RequiredUI:RUser InteractionS:UScopeC:NConfidentialityI:HIntegrityA:NAvailabilityWeaknesses
Affected Products
Attack Graph
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Exploitability
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View exploit detailsMITRE ATT&CK
1 techniqueReferences
Timeline
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