// For flags

CVE-2021-41267

Webcache Poisoning in Symfony

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

Symfony/Http-Kernel es el componente del núcleo HTTP de Symfony, un framework PHP para aplicaciones web y de consola y un conjunto de componentes PHP reusables. Los encabezados que no forman parte de la lista permitida "trusted_headers" son ignoradas y protegen a los usuarios de ataques de "Cache poisoning". En Symfony versión 5.2, los mantenedores añadieron soporte para los encabezados "X-Forwarded-Prefix", pero este encabezado era accesible en SubRequest, incluso si no era parte de la lista permitida "trusted_headers". Un atacante podría aprovechar esta oportunidad para falsificar peticiones que contengan un encabezado "X-Forwarded-Prefix", conllevando aun problema de envenenamiento de la caché web. Las versiones 5.3.12 y posteriores presentan un parche para asegurar que el encabezado "X-Forwarded-Prefix" no es reenviado a las subpeticiones cuando no es confiable

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-09-15 CVE Reserved
  • 2021-11-24 CVE Published
  • 2024-08-04 CVE Updated
  • 2024-08-09 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Sensiolabs
Search vendor "Sensiolabs"
 Symfony
Search vendor "Sensiolabs" for product "Symfony"
 >= 5.2.0 < 5.3.12
Search vendor "Sensiolabs" for product "Symfony" and version " >= 5.2.0 < 5.3.12"
-
Affected