Why is my SSH X Window forwarding broken?
SSH into your destination:
ssh -vv -X <hostname>
If you see a line near the end that says “debug1: Remote: No xauth program; cannot forward with spoofing.“, you need to install xauth and reconnect. In Debian, run:
apt-get install xbase-clients
Next, ensure that you’re getting a DISPLAY variable through:
If that command outputs just a blank line, X forwarding is probably being denied by the server. Edit your sshd_config (/etc/ssh/sshd_config on Debian) and change/add the line:
If you change this, you’ll need to restart your SSH server:
Once your DISPLAY is being passed correctly, some programs may run but act oddly (”Gdk-error: […] BadAtom”, etc.) SSH uses “SECURITY” extensions by default, and some programs don’t work correctly with them. Try:
ssh -Y <hostname>
Note that this command may expose your local machine to compromise if someone malicious is in control of the host you’re connecting to.