** Tags removed: server-next -- 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/1863930
Title: SSH 1.99 clients fail to connect to openssh-server 1:7.6p1-4ubuntu0.3 Status in openssh package in Ubuntu: Fix Released Status in openssh source package in Bionic: Incomplete Bug description: [Impact] * The version check in ssh was broken no more following RFC 4253 and thereby denying some clients that it shouldn't * Upstream fixed that and this is backporting the changes to bionic. [Test Case] # Prep * configure the ssh server to generally work # Testcase $ wget https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/1863930/+attachment/5332797/+files/test_bug_1863930.py $ apt install python3-paramiko $ python3 test_bug_1863930.py localhost (or whatever your host is) Will report "Server is not patched." or "Server is patched. * for an extra regression check it might be worth to do some "normal" ssh connections as well [Regression Potential] * The change is very small and reviewable as well as being upstream and in all Ubuntu releases >=Cosmic for a while now so it seems safe. If anything the kind of regression to expect is that some former (wrong) connection denials will then succeed. I can only think of that being an issue in test suites but not in the real world. [Other Info] * n/a -- SSHD closes the connection and logs the error message below when a client presents a protoversion of "1.99": Protocol major versions differ for X.X.X.X port X: SSH-2.0-OpenSSH_7.6p1 Ubuntu-4ubuntu0.3 vs. SSH-1.99-XXX RFC 4253 only states that clients should treat a server's protoversion of "1.99" as equivalent to "2.0"; however, some backward-compatible clients send a protoversion of "1.99" and expect the server to treat it as "2.0". This regression was introduced in openssh-portable 7.6p1 from commit 97f4d3083; fixes were implemented in commits 9e9c4a7e5 and c9c1bba06. I've attached a patch with both of those fixes. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/1863930/+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
