> 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 Lista Negra Notas sobre SSRF com Filtragem Baseada em Lista Negra para laboratórios da PortSwigger Web Security Academy, incluindo fluxo de exploração, teste de payloads, validação no Burp Suite e contexto de remediação. ### SSRF com filtro de entrada baseado em blacklist 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 de defesa fracos baseados em blacklist devem ser contornados. #### Análise e Circunvenção Ao substituir o `stockApi` parâmetro para apontar diretamente para o admin local, a requisição é recusada: ``` stockApi=https://localhost/admin ```
Para contornar a blacklist 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 se concentra principalmente nessa string específica.
```javascript stockApi=http://127.1/%2561dmin stockApi=http://127.1/%2561dmin/delete?username=carlos ``` --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://hacking-notes.jord4n.pro/pt-br/web/ssrf/ssrf-with-blacklist-based-filter.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.