CVE-2021-21424 PoC — Prevent user enumeration using Guard or the new Authenticator-based Security

Source

https://github.com/moften/CVE-2021-21424

Associated Vulnerability

Title:Prevent user enumeration using Guard or the new Authenticator-based Security (CVE-2021-21424)
Description:Symfony is a PHP framework for web and console applications and a set of reusable PHP components. The ability to enumerate users was possible without relevant permissions due to different handling depending on whether the user existed or not when attempting to use the switch users functionality. We now ensure that 403s are returned whether the user exists or not if a user cannot switch to a user or if the user does not exist. The patch for this issue is available for branch 3.4.

Description

 El WebProfiler de Symfony expone rutas internas del servidor si no está deshabilitado en producción

Readme

# CVE-2021-21424

Directory Traversal y exposición de archivos
	•	CVE-2021-21424
	•	Descripción: El WebProfiler expone rutas internas del servidor si no está deshabilitado en producción.
	•	Versiones afectadas: Symfony 2.8 a 5.x.
	•	Bypass típico: acceso directo a /app_dev.php/_profiler/.


	Resumen del CVE-2021-21424
	•	CVE: 2021-21424
	•	Componente: Web Profiler / Dev Toolbar
	•	Impacto: Exposición de información sensible (entorno, rutas, parámetros)
	•	Requisito: Que /app_dev.php, /_profiler o /_wdt estén accesibles desde producción.
	•	Riesgo: Permite escalado de privilegios, acceso a variables de entorno, credenciales, rutas internas, debugging de requests y profiling de controladores.

File Snapshot

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