Alright, so I pulled the data from scans.io, There's actually 82,650 devices on the open Internet claiming support for <=SSH-1.5, generally routers. Top 20 on that is: $ head -n 20 ssh1_versions.txt 39148 SSH-1.5-Cisco-1.25 14477 SSH-1.5-HUAWEI-VRP3.1 10571 SSH-1.5-1.0.0 4634 SSH-1.5-HUAWEI-VRP-3.10 3284 SSH-1.5-1.2.33 2965 SSH-1.5-VRP-3.3 1836 SSH-1.5-VRP-3.4 1125 SSH-1.5-Server 1034 SSH-1.5-X 1022 SSH-1.5-1.2.22j4rad 753 SSH-1.5-1.2.26 538 SSH-1.5-OpenSSH_4.4 422 SSH-1.5-SSH 379 SSH-1.5-HUAWEI-VRP5.0 304 SSH-1.5-OpenSSH_2.3.0_Mikrotik_v2.9 270 SSH-1.5-SSHServer 269 SSH-1.5-1.2.27 223 SSH-1.5-OpenSSH_3.7.1p2 175 SSH-1.5-Huawei 136 SSH-1.5-LtSSH_3.6 Of course, this is out of a total of 15,124,618 SSH servers, granting a compat rate greater than 99.99%. However, distinctly and painfully unlike SSL/TLS, SSH is successfully deployed and used on internal networks that cannot be scanned from the open Internet. It's also a protocol of fairly critical importance, uniquely used in a "hop by hop" manner in which each hop actually has to work. 7.3% of Cisco routers on the open Internet only support SSHv1. The numbers inside private networks are likely to be higher. I can see the argument for pushing people to upgrade, but not by surprise in a minor version. If SSH is going to block old insecure versions it has a much bigger problem, because upgrade rates on SSH on the Internet are actually not fantastic. Here's the top 40 across all versions of SSH: $ head -n 40 sshall_versions.txt 2412684 SSH-2.0-OpenSSH_5.3 984056 SSH-2.0-OpenSSH_4.3 936855 SSH-2.0-dropbear_0.51 854624 SSH-2.0-dropbear_0.46 798414 SSH-2.0-OpenSSH_6.0p1 790303 SSH-2.0-OpenSSH_6.6.1p1 771396 SSH-2.0-OpenSSH_5.9p1 465647 SSH-2.0-OpenSSH_5.5p1 430372 SSH-2.0-ROSSSH 338577 SSH-1.99-Cisco-1.25 337282 SSH-2.0-OpenSSH_6.2 325681 SSH-2.0-dropbear_0.52 315864 SSH-2.0-dropbear_2012.55 305623 SSH-2.0-dropbear_2013.58 178282 SSH-2.0-OpenSSH 169613 SSH-2.0-OpenSSH_4.7 162892 SSH-2.0-OpenSSH_5.1p1 160225 SSH-2.0-OpenSSH_5.3p1 150068 SSH-2.0-Cisco-1.25 141795 SSH-2.0-OpenSSH_5.1 130653 SSH-2.0-OpenSSH_6.7 122612 SSH-2.0-RomSShell_4.31 121542 SSH-2.0-homepl 116630 SSH-2.0-OpenSSH_5.8 112202 SSH-2.0-OpenSSH_6.4 98829 SSH-2.0-dropbear_2011.54 96457 SSH-2.0-OpenSSH_4.3-HipServ 88471 SSH-2.0-OpenSSH_5.2 88444 SSH-2.0-OpenSSH_5.9 86001 SSH-2.0-dropbear_0.48 69497 SSH-2.0-OpenSSH_5.4p1 67565 SSH-1.99-DOPRA-1.5 60749 SSH-2.0-OpenSSH_6.1 59323 SSH-2.0-ARRIS_0.50 59103 SSH-2.0-lancom 58497 SSH-2.0-Trendchip_0.1 57757 SSH-2.0-OpenSSH_5.6 55951 SSH-2.0-OpenSSH_6.2p2 54750 SSH-2.0-dropbear_0.50 52685 SSH-2.0-OpenSSH_6.6p2-hpn14v4 This is specifically a scenario where OpenSSH should measure twice and cut once. The worst case scenario is that people update even less than they already do, because who knows what servers are no longer important enough to require connectivity to next. Start the discussion, absolutely, but let's not forget even SSHv1 is miles better than Telnet, and this just isn't the rapidly updating consumer browser ecosystem we're messing with here. --Dan On Tue, Mar 24, 2015 at 9:16 PM, Damien Miller <djm@xxxxxxxxxxx> wrote: > On Tue, 24 Mar 2015, Nico Kadel-Garcia wrote: > > > If it's disabled by default in any major distributions, it's going > > to break a lot of git repositories, svn+ssh repositories, and rsync > > environments. > > The chronology doesn't support this. > > When Subversion 1.0 was released in 2004, OpenSSH had been defaulting to > protocol v.2 for almost three years. > > git was first released two years later, at which time v.2 had been the > default for over five years. > > Seriously, protocol 2 became the default in *2001* and the old protocol > has been disabled for new sshd installs for the last eight years. If > anything, we've moved way too slowly. > > > Can it wait until version 7, instead of being slipped into a minor > > update? > > Our version number has been a simple counter for years; the first digit > of the version has no significance beyond that. > > Distributions will make their own decisions about what to support and > they already ship far more intrusive changes than flipping a configure > switch. I hope they ship a "openssh-ssh1" package instead of just > setting it back through. > > -d > _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev