I wanted to check if other releases are affected as well, but it was interesting as it didn't show up even on a Trusty container ssh'ing to itself.
ubuntu@t:~$ unset DISPLAY ; ssh -X ubuntu@localhost 'dpkg -l openssh-client | grep ii' ubuntu@localhost's password: ii openssh-client 1:7.2p2-4ubuntu2.4 amd64 secure shell (SSH) client, for secure access to remote machines No issue, to be seen. @Santiago - do you know what the secret ingredient to trigger the bug might be? ** Bug watch added: Debian Bug tracker #908652 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=908652 ** Also affects: openssh (Debian) via https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=908652 Importance: Unknown Status: Unknown -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to openssh in Ubuntu. https://bugs.launchpad.net/bugs/1792231 Title: openssh-client: 'DISPLAY "(null)" invalid; disabling X11 forwarding' Status in openssh package in Ubuntu: Fix Released Status in openssh source package in Trusty: Triaged Status in openssh package in Debian: Unknown Bug description: affects ubuntu/openssh Hi, This bug is present in openssh in ubuntu trusty, I haven't tested other releases. When X11 forwarding is enabled (via ssh_config, or via -X), but no DISPLAY is available, ssh client produces this warning: DISPLAY "(null)" invalid; disabling X11 forwarding root@ubuntu-trusty:/# unset DISPLAY ; ssh -X ubuntu@localhost 'dpkg -l openssh-client | grep ii' ubuntu@localhost's password: DISPLAY "(null)" invalid; disabling X11 forwarding ii openssh-client 1:6.6p1-2ubuntu2.10 amd64 secure shell (SSH) client, for secure access to remote machines The bug was introduced by the changes to fix CVE-2016-1908. This upstream change fixes it: https://anongit.mindrot.org/openssh.git/commit/?id=5658ef2501e785fbbdf5de2dc33b1ff7a4dca73a See https://bugs.debian.org/908652 Cheers, -- S To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/1792231/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
