URL Shortener Open Redirect
By @gorkaE-commerce con servicio de acortamiento de URLs que acepta cualquier destino sin validacion, creando redirecciones abiertas con URLs del dominio confiable.
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:2001
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 servicio de URL shortening integrado.
La vulnerabilidad
POST /api/shorten acepta cualquier URL sin validacion. Genera un shortlink del dominio confiable que redirige al destino malicioso.
Cadena de ataque
1. POST /api/shorten con url=https://evil.com
2. Obtener URL corta: https://skyhaven.com/s/abc123
3. Compartir URL corta (parece confiable)
4. Victima clica → redirigida a evil.com
Solucion interactiva
Accede a /writeup dentro de la aplicacion para una guia paso a paso con botones interactivos.
Flag
(URL acortada redirige a sitio externo)
Remediacion
- Bloquear URLs externas sospechosas
- Mostrar pagina de advertencia antes de redirigir
- Rate limiting en creacion de short URLs
