OpenSSH 7.4 Removes Server Support for the SSH-1 Protocol, Adds New Features

OpenSSH 7.4 has been released today, December 19, 2016, as the latest and most advanced stable release of the open-source and portable 100% complete SSH protocol 2.0 implementation used on Linux, BSD, and other Unix-like platforms.

OpenSSH 7.4 is here four and a half months after the release of OpenSSH 7.3, and it promises to be primarily a bugfix release that addresses many of the security issues discovered since OpenSSH 7.3. But first, it looks like this version includes various under-the-hood changes that may affect existing configurations.

For example, it removes support for the the SSH version 1 protocol as SSH2 is a more secure, efficient, and portable version of SSH (Secure Shell), which delivers SSH-encrypted SFTP functionality. It also removes 3des-cbc from the client's default proposal, as well as support for pre-authentication compression.

"Doing compression early in the protocol probably seemed reasonable in the 1990s, but today it's clearly a bad idea...