11 comments

  • dust42 4 minutes ago
    > We are making this release as fast as possible (we learned of the problem yesterday) because we have recently observed multiple cases of rapid bug rediscovery by AI agents, sometimes within hours, and so now consider long embargo periods to be a dangerous practice that primarily benefits attackers.

    I think this will likely become standard. Nevertheless, a few stormy months are ahead.

    • amluto 1 hour ago
      Wow, what a bug. I expect the exploit is literally as simple as trying to ssh in as a user with the password has ‘*’ in /etc/shadow and typing anything as the password.

      To the extent that systems that are configured in the vulnerable manner exist in the wild, I’m surprised they weren’t exploited years ago by trivial ssh bots.

      P.S. Wow, I’m reminded of just how awful traditional UNIX-y C APIs and code are.

      P.P.S. The musl code in question is nuts. The API it implements is awful. Seriously, here’s the manpage:

      https://man.archlinux.org/man/crypt.3.en

      You can’t call this function correctly. sshd’s “fix” is basically to assume that a too-short return is an error return instead of a success return.

      PAM is also awful, but this is worse.

      • throwa356262 3 hours ago
        musl only, the quick fix:

             PasswordAuthentication=no
        
        
        Which is a good advice in general.
        • solyin 1 hour ago
          How do you break back into your digital life? You wake up in a strange place. Something happened. Everything's gone. No wallet/keys/smartphone/tablet/laptop. How would you get back into your digital life given only a laptop with access to the Internet, unless something, somewhere is passwordauthenticate=yes.
          • MPSimmons 1 minute ago
            Does this happen to you a lot? You may have other issues
            • jareklupinski 50 minutes ago
              > You wake up in a strange place. Something happened. Everything's gone. No wallet/keys/smartphone/tablet/laptop.

              at this point the _last_ thing i care about is my email.

              where am i? am i ok? how are my friends/loved ones?

              once those are in place, it becomes clearer how to get back to "normal"

              • denkmoon 52 minutes ago
                I walk to my pc and type ssh-keygen. If i can’t do that I’ve got bigger problems. “I must be able to recover remotely using a memorised credential” is a terrible requirement.
                • fn-mote 39 minutes ago
                  The somewhere for password authentication is a place you have physical access. Not ssh.
                  • mr_mitm 25 minutes ago
                    I log in via console, either physical or virtual (the latter requires MFA though)
                    • worksonmine 5 minutes ago
                      A scenario where all the backups are gone and the server is somehow the only thing that survived is not a very plausible one.
                      • INTPenis 1 hour ago
                        Yeah your vault has password authentication. Your password manager in other words. Your vault is where you store your private ssh keys, and or the passwords for the keys.
                        • viraptor 53 minutes ago
                          Remotely: An encrypted file with a seed / master passwords to all the other data, published under a public url you can remember, but not linked anywhere and not listed.

                          Locally: Same, but printed out, laminated, in a safe place with other documents.

                          • petesergeant 40 minutes ago
                            1Password subscription and the memorized key. 1Password is the only place my ssh private keys are stored.
                            • uresolame 18 minutes ago
                              1PaSsWoRd... SuBsCripTIon... it's just unbelievable how pathetic today's average HN user is...
                              • illusive4080 11 minutes ago
                                Avoid this kind of behavior on HN; we are not the community for attacking each other. Your comment is not helpful to further the conversation. You could have made a point about subscriptions being antithetical to the ethos of open source culture, but instead you attacked the user and mocked him/her.
                          • patadura 43 minutes ago
                            imo this is a good advice only if the devices that connect to the server have their home encrypted and ssh private key protected.
                          • asdfsa32 1 hour ago
                            Who does PasswordAuthentication=yes in this day and age anyway.
                            • mhitza 23 minutes ago
                              If you run a cockpit service on your server you will need password authentication enabled, unfortunately.
                              • krystalgamer 22 minutes ago
                                it's the default for most systems. I can't remember a time I had to not turn it off.
                                • ectospheno 57 minutes ago
                                  People who use AuthenticationMethods "publickey,password"

                                  You must present a key first after which you must enter a password.

                                  • rvz 42 minutes ago
                                    Just do no password at all.
                                    • ectospheno 35 minutes ago
                                      Putting the one in 1fa? No thanks.
                                  • walrus01 34 minutes ago
                                    As this is apparently affecting openwrt, probably a fair number of openwrt users, if I had to guess
                                  • K0nserv 37 minutes ago
                                    This looks terrible for musl, what a collection of terrible decisions on their part. I guess I'm staying away from it.
                                    • sheepscreek 25 minutes ago
                                      To err is human. There’s no escaping it, I’m afraid.
                                    • jmclnx 42 minutes ago
                                      >We consider the root cause of this bug to be outside OpenSSH itself, but we're in a good position to deliver a mitigation quickly.

                                      So not a ssh issue but an issue specific to Linux using "musl libc without PAM".

                                      • crest 2 hours ago
                                        I'm sure some people running lightweight containers just had a heart attack.
                                        • smw 1 hour ago
                                          I would imagine the vast majority of lightweight containers don't contain an ssh server?
                                        • phoronixrly 2 hours ago
                                          I presume Dropbear, thus musl-based OpenWrt routers are also not affected? Not that Dropbear has been an example in that regard.
                                          • mijoharas 34 minutes ago
                                            There is this write-up/fancy page from the person who found the vulnerability[0] (HN discussion[1], how I found this thread).

                                            At the bottom of that it says dropbear is unaffected.

                                            > on debian, ubuntu, fedora or anything else with glibc? going through pam? dropbear? openbsd? you're fine

                                            [0] https://sshhole.com/

                                            [1] https://news.ycombinator.com/item?id=50378228

                                            • manwe150 2 hours ago
                                              Since after you posted, various people in the thread have reported dropbear is not affected
                                            • keepitupkitty 1 hour ago
                                              [flagged]
                                              • jordiburgos 2 hours ago
                                                Workaround? Why not a fix?
                                                • ale42 2 hours ago
                                                  AFAIU because the bug is in musl and not in OpenSSH
                                                • entuno 1 hour ago
                                                  Seems slightly confusing that the OpenSSH release notes page says:

                                                  > This release contains a critical security workaround that affects Linux systems that use the musl libc and PAM disabled.

                                                  But that there's nothing about it on their security page.

                                                  Even if it's not technically a bug in their code, the fact that they've made a "critical" release to address it suggests that it should probably be listed on the security page as well. But maybe (hopefully) they just haven't updated the security page yet.