> 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/permissions/etc-passwd-write-abuse-linux-privilege-escalation.md).

# Abuso de escrita em /etc/passwd - Escalada de privilégios no Linux

## O que é

A escalada de privilégios baseada em permissões explora arquivos graváveis, propriedade fraca, segredos expostos ou caminhos sensíveis que deveriam ser controlados apenas pelo root. Pequenos erros de permissão podem se tornar acesso root direto quando afetam arquivos de autenticação ou caminhos de execução privilegiados. Esta página específica foca em **Gerenciamento de permissões (/etc/passwd)** e mantém o fluxo de exploração prático: identifique a condição, valide-a com segurança e então execute o payload menor necessário para comprovar o impacto.

## Enumeração

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

```bash
find / -writable 2>/dev/null
ls -la /etc/passwd /etc/shadow 2>/dev/null
```

## Exemplos

Se filtrarmos os arquivos pela \*\*gravabilidade\*\* do sistema, então o /etc/passwd

```bash
find / -writable 2>/dev/null
```

<figure><img src="/files/2bfb8200a9cd85bb6a96470e272a6f5735ae85cd" alt=""><figcaption></figcaption></figure>

<div data-full-width="true"><figure><img src="/files/8cea81517a702672f9adb670bc269d36dbac3834" alt=""><figcaption></figcaption></figure></div>

Com **openssl**, se criarmos uma senha, ele a retorna no formato SSL

```bash
openssl passwd
```

<div data-full-width="true"><figure><img src="/files/12f36b9b8cfe38e305a8df6bb55c50d4cc6a3828" alt=""><figcaption></figcaption></figure></div>

Colamos essa string no usuário root e o sistema a lerá de /etc/passwd antes de /etc/shadow:

<figure><img src="/files/77c8beb61f5ffc4dd0f08cabb2bbc83bb6faef59" alt=""><figcaption></figcaption></figure>


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