# Traffic Lights W
>Can you figure out what’s going on with this shady company? https://traffic-light-w.web.hsctf.com/
You are given a page where you can upload firmware to some docker containers.
![](main.png)
When you clock on the "Upload Firmware" button, you are able to upload XML firmware to that container.
![](xml.png)
The example firmware is below.
```xml
<root>  <content>Red</content></root>```
When you upload that, you are echoed back "Red".
I tried some xxe payloads I looked up online, and one of them worked! Payload is below:
```xml
 ]><root>  <content>&xx;;</content></root>```
![](passwd.png)
The challenge was to figure out what suspicious thing the company was doing, so I wondered what would happen if I connected to one of the docker containers, so I did just that, and that gave us the flag!
```xml
 ]><root>  <content>&xx;;</content></root>```
![](sol.png)
Flag: `flag{shh_im_mining_bitcoin}`