OAuth Authorization Code Theft via Open Redirect
By @gorkaE-commerce con proveedor OAuth falso que acepta cualquier redirect_uri, permitiendo robar el codigo de autorizacion via redireccion abierta.
This hack was reported with no reward
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Despliegue
# Opcion 1: autodeploy
./autodeploy.sh
# Opcion 2: manual
docker compose up --build
# Acceder
http://localhost:2003
Compatible con macOS, Linux y Windows (Docker Desktop / WSL).
Para parar:
./autodeploy.sh destroy
# o: docker compose down -v
Contenido del Lab
La aplicacion
SkyHaven con autenticacion OAuth y un proveedor de identidad simulado.
La vulnerabilidad
El endpoint /oauth/authorize acepta redirect_uri sin validar contra una whitelist. El atacante puede especificar su propio servidor como destino y recibir el codigo de autorizacion de la victima.
Cadena de ataque
1. Analizar flujo OAuth normal
2. Modificar redirect_uri a https://attacker.com/callback
3. Enviar link a victima
4. Victima autoriza → codigo enviado a attacker
5. Usar codigo para obtener token de acceso
Solucion interactiva
Accede a /writeup dentro de la aplicacion para una guia paso a paso con botones interactivos.
Flag
(codigo de autorizacion OAuth robado)
Remediacion
- Validar redirect_uri contra whitelist estricta
- Comparacion exacta de redirect_uri registradas
- No usar wildcards en URIs de redireccion
