> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/es/privesc/cron-jobs/modified-bash-script-cron-job-linux-privilege-escalation.md).
# Trabajo cron de script Bash modificado - Escalada de privilegios en Linux
Notas de trabajos cron - script modificado (Bash) para la escalada de privilegios en Linux, con pasos de enumeración, ejemplos de explotación y validación enfocada en informes.
## Qué es
Los cron jobs crean vías de escalada de privilegios cuando las tareas recurrentes de root ejecutan scripts editables, rutas relativas inseguras o procesadores vulnerables. La clave es demostrar que un usuario con pocos privilegios controla algo que ejecutará una tarea programada con privilegios. Esta página específica se centra en **Cron Jobs - Script modificado (Bash)** y mantiene práctico el flujo de explotación: identifica la condición, valídala de forma segura y luego ejecuta la carga útil mínima necesaria para demostrar el impacto.
## Enumeración
Empieza confirmando el contexto local y la configuración errónea exacta antes de ejecutar la ruta de explotación.
```bash
cat /etc/crontab
ls -la /etc/cron.*
systemctl list-timers --all
```
## Ejemplos
En este caso, encontramos que un script.sh \*\*se está ejecutando\*\*:
Lo que haremos es **modificar** el script con el siguiente contenido:
```bash
sleep 2
chmod u+s /bin/bash
```
Ejecutamos Bash con el **p** parámetro de privilegio:
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