Burp Proxy: Non-Proxy Aware Devices

TL;DR

Get traffic from a device that doesn’t know about your Burp proxy flowing through it using SSH tunneling. This guide shows you how to set up an SSH tunnel as a SOCKS proxy for Burp.

Setting Up the SSH Tunnel

1. Find Your Server’s IP Address: You’ll need the public IP address of your server (the machine running Burp). If you don’t know it, you can use a service like WhatIsMyIP.
2. Connect via SSH: Use an SSH client (like PuTTY on Windows or the built-in `ssh` command on macOS/Linux) to connect to your server.

   ssh username@server_ip_address

3. Create the SOCKS Proxy Tunnel: Once connected, create an SSH tunnel that forwards traffic as a SOCKS proxy. Replace local_port with a port number on your local machine (e.g., 1080) and server_ip with your server’s IP address.

   ssh -D local_port username@server_ip_address

4. Configure Burp Proxy: In Burp Suite, go to the ‘Proxy’ tab → ‘Options’.
   • Select the ‘Proxy Listeners’ sub-tab.
   • Add a new listener.
   • Set the ‘Bind address’ to 127.0.0.1 (localhost).
   • Set the ‘Port’ to the same local_port you used in the SSH tunnel command.

Configuring Your Device

1. Configure System-Wide Proxy: On your non-proxy aware device, configure its network settings to use a SOCKS proxy.
   • SOCKS Host: 127.0.0.1 (localhost)
   • Port: The same local_port you used in the SSH tunnel and Burp configuration.
   • Proxy Type: SOCKS5 is generally preferred, but SOCKS4 might work if SOCKS5 isn’t supported.
2. Test the Connection: Open your device’s web browser and visit a website. Check Burp Suite to see if the traffic is being intercepted.

Troubleshooting

• Firewall Issues: Ensure that your server’s firewall allows connections on port 22 (SSH) and any other ports required by Burp.
• SSH Configuration: Check your SSH server configuration (`/etc/ssh/sshd_config`) to ensure it allows TCP forwarding. Look for the `AllowTcpForwarding` directive; it should be set to ‘yes’.
• Burp Listener Binding: Make sure Burp is listening on the correct interface (127.0.0.1) and port.