CVE-2021-41267 Webcache Poisoning in Symfony

2021-11-2418:55:17

CWE-444

GitHub_M

www.cve.org

6.5 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

HIGH

Availability Impact

NONE

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

0.001 Low

EPSS

Percentile

39.2%

JSON

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.

CNA Affected

[
  {
    "product": "symfony",
    "vendor": "symfony",
    "versions": [
      {
        "status": "affected",
        "version": ">= 5.2.0, < 5.3.12"
      }
    ]
  }
]