Sshole

(sshhole.com)

352 points | by josemrb 1 hour ago

28 comments

  • BoppreH 21 minutes ago
    In-band signaling strikes again. * should not have been used as special value, neither for "no password" in /etc/passwd nor "error while hashing the password" in crypt. I'm afraid we'll find many more of these abuses, specially in string manipulations. The null was ok, an exception (or equivalent) better, and Result<T> (or equivalent) best.
  • nxobject 38 minutes ago
    Above all, I’m a little sad that the musl developers decided to make a lot of “well it’s convenient” changes to core crypto functions — at least without the level of auditing that would have caught this! It’s tarnished their reputation in my eyes a little.
    • trebligdivad 21 minutes ago
      In many ways each individual decision makes some sense; wanting to stop loads of programs being affected by a (remotely triggerable?) crash wanting to avoid time based attacks wanting to be able to set accounts to not have a password

      Each one relies on a perfectly valid argument - that * can't match because we all know it'll be rejected by the other thing.

      • Retr0id 10 minutes ago
        > Each one relies on a perfectly valid argument - that * can't match because we all know it'll be rejected by the other thing.

        But that's not a perfectly valid argument, and it never was.

      • zarzavat 8 minutes ago
        The real problem here is the C language. Our industry should have dumped it a long time ago and we’re now paying the price of prevarication.
    • rustyhancock 26 minutes ago
      I think everyone is over fixated on AI finding complex bugs beyond a typical person's understanding either to locate or exploit.

      I think for any one of those bugs there might simply be half a dozen footguns or bugs that once it's spelled out you wonder how anyone let it slide.

      I think that's the case where LLMs might indentify most.

      It's challenging though as the current AI audits produce so many false positives it's hard to know when it's being pedantic or when it's genuinely caught a human being a bone head

    • semiquaver 22 minutes ago
      A little?!? I’m sorry, but musl is a joke, this is yet another proof of that fact, and I have no idea why anyone uses it in production, they have only themselves to blame after the many warning signs.
  • scandinavian 38 minutes ago
    Did anyone get it to work? I tried on the official alpine docker image, enabled password login for root. The shadow entry has ! as password by default, this didn't work with a > 256 character password (i also did passwd -l which also does !). I manually changed it to * and it still didn't work.

    Am I doing anything wrong here?

    OpenSSH_10.3p1, OpenSSL 3.5.9 29 Sep 2026

    PRETTY_NAME="Alpine Linux v3.24"

    • hagbard_c 1 minute ago
      No, didn't work for me open OpenWRT x64 running in a container but that is probably 'cause I'm using dropbear instead of openssh-server. That's what OpenWRT uses by default so the impact there will be minimal assuming that most installations don't change to openssh-server - it isn't installed by default.
    • atmosx 22 minutes ago
      Nope, wasn’t able to reproduced it in my firecracker VM, which isn’t publicly accessible anyway.
    • f311a 15 minutes ago
      As far as I understand, it wont work on default setups. You need musl-c, no pam and openssh.
    • q3k 7 minutes ago
      Also didn't have much luck on Alpine 3.20.10 with OpenSSH_9.7p1 which I've freshly installed from an official ISO.

      Last two entries in /etc/shadow:

          test:*:20762:0:99999:7:::
          q3k:$6$snip.GgDQNTrqqX.A0:20762:0:99999:7:::
      
      SSHing into test@ with one 'wrong' password then one 'long' password doesn't work. I have UsePAM no and PasswordAuthentication yes in my sshd_config.
    • emayljames 20 minutes ago
      Did you try one incorrect standard password fail first?
  • neuroticnews25 51 minutes ago
    That's a well-made site, yet I feel nothing.
    • tasuki 33 minutes ago
      Maybe that's on you though. I enjoyed it, though the discrepancy between the `*sshole` name and the `sshhole.com` domain made me twitch. How is anyone[0] obsessive enough to find this and write it up and yet not obsessive enough to make the amount of `h` consistent?

      [0]: Be they human or LLM. Or an entity with any proportion of the two. I do not judge nor discriminate.

      • glibg10b 27 minutes ago
        Look closely. The second h is behind the word and almost as dark as the background
        • tasuki 23 minutes ago
          Oh. Thank you!
    • cpach 48 minutes ago
      LLM output fatigue?
      • amelius 5 minutes ago
        Apple sideways traffic light fatigue.
      • riffraff 19 minutes ago
        I didn't hate the writing even if it's AI, but I deeply disliked the animations. I don't know if that's LLM fatigue or not.
    • jonstewart 39 minutes ago
      What is dead can never die. All blueteamers are ironborn these days.
  • traceroute66 25 minutes ago
    To be fair, I have less than zero sympathy for anyone who runs SSH on any platform without `PasswordAuthentication=no` in 2026.

    Its not asking for trouble, it is there will be trouble, not if but when.

    As for the people who say "well, I run SSH on port 942329053052". Well guess what, the bots make short work on that. We tried it at $work as an experiment, multiple bots found it in less than a couple of hours. That's why your SSH config must be hardened, preferably running on a hardened OS too.

    • Ecco 5 minutes ago
      How is password auth weaker than key auth? Bugs in auth code can happen in both pathways. And apart from stupidly short passwords both should be equally impossible to brute-force.

      In other words, conceptually, at the end if the day, isn’t a key just another name for a password, really?

      • jadamson 2 minutes ago
        Keys stay on your device.
    • znnajdla 20 minutes ago
      This particular bug works even with password authentication turned off.
      • sjamaan 11 minutes ago
        Where did you get that idea? The entire bug is about password hashing. With password auth off, that's not even attempted.
      • tialaramex 9 minutes ago
        Bug > are password logins still on? they are by default

        You > This particular bug works even with password authentication turned off.

        No. The bug is related to password authentication. If you do not have password authentication then you are not affected.

        What freaks some people out is they chose parameters where they do have password authentication but they expect to always fail. That's a bad choice, like OK you did fit a cheap manual keyhole, but you threw the keys away thinking now nobody can open that - you realise somebody with a cheap jiggler can open it right ?

      • traceroute66 17 minutes ago
        > This particular bug works even with password authentication turned off.

        Does it ?

        Somebody here has already said "You can set PasswordAuthentication=no or update to remediate"

        We don't use musl at $work anyway, so I've no means to test.

    • ghm2180 17 minutes ago
      100% and with local tool calls many AI systems will do ssh "for you" and end run around any security theatre that you may have going on with LLMs.
  • 0x0 9 minutes ago
    For OpenWRT, AsusWRT etc, I believe they use dropbear ssh by default instead of OpenSSH, which apparently isn't affected?
  • hypfer 55 minutes ago
    What is out there that uses musl without PAM and hosts an OpenSSH SSHd with PasswordAuthentication?

    As in: "Actually out there"

    The hypothetical Alpine exists, yes, but what runs that like that?

    • Bender 45 minutes ago
      What is out there that uses musl without PAM and hosts an OpenSSH SSHd with PasswordAuthentication?

      Possibly public SFTP servers. I have allowed null passwords in the past for anonymous public SFTP and I run Alpine Linux exclusively for my servers both VM's and physical. The shadow package (PAM) did not get installed by default. I installed it but I had to specify it in the installation.

      I will activate one for people to play around with:

          sftp [email protected]
      
      There's no firewall. Hack away HN.

          PasswordAuthentication yes
          PermitEmptyPasswords yes
    • jbyers 52 minutes ago
      A large number of Docker containers?

      Edit: Sure, a small minority presumably run sshd under these conditions. But a small minority times the number of Alpine containers running in the world gets to a large absolute number.

      Edit 2: You really don't need to look very hard to find public container examples at million-download scale.

      • ekidd 48 minutes ago
        Many, many Docker containers rely on "docker exec" or the kubectl equivalent to gain CLI access when needed. To have sshd in an Alpine Docker container, you're generally need to be running init and a bunch of demons, not just a single standalone service.

        I'm guessing in practice relatively few people are actually exposed. But if they are, it's catastrophic.

      • hypfer 50 minutes ago
        Docker containers that run sshds?
      • stingraycharles 46 minutes ago
        Docker containers run sshd?
    • figassis 30 minutes ago
      Agent sandboxes today probably
  • NavinF 19 minutes ago
    Wow. I wonder which of the common fuzzers would have found this a decade ago. If literally any password over 256 chars works, that means nobody has ever fuzzed openssh on musl linux
  • illusive4080 56 minutes ago
    From the other thread’s source [1], it affects musl without PAM. You can set PasswordAuthentication=no or update to remediate.

    [1] https://hachyderm.io/@damienmiller/117563026759098135

  • draxen 29 minutes ago
    I avoided using alpine-based containers ever since finding out a lot of Linux server software is actually Linux + SystemD software. The union set API of both Linux and SystemD seems to be the default "Linux API" today.
    • sam_lowry_ 26 minutes ago
      I use alpine-based containers whenever I can just to keep the world safer from SystemD rotting Linux.

      Never enabled sshd there... except on my PostmarketOS PineBook Pro... oh shit!

      • andunie 21 minutes ago
        What is the argument against systemd?

        Is it mainly that it is too big?

        I feel like everybody still loves the unix philosophy, but the previous tools were too bad, systemd just filled user demand for easier tools.

        The moment someone makes a pid 1 software that is good and still modular, open and pluggable I think that will be an instant success.

  • MarkBlah 4 minutes ago
    Haha insane, great find and write up
  • ctrlaltdileep 11 minutes ago
    That's kind of shocking. I guess the swarm of AI related vulnerability findings continues.
  • throooooo 23 minutes ago
    The bugs and commits that "fix" them reveal somewhat of a shitshow for how musl is managed. All projects have bugs, but I can't help but question why the wheel was reinvented here. Many toes have been stubbed along the way.
  • paaloeye 20 minutes ago
    Not the worst site, but it's clearly a publicity machine from wakefield.co, whom I haven't heard of. Also, exploitation conditions are super narrow, albeit, any password is wild.
  • RVuRnvbM2e 30 minutes ago
    Wait so musl, famously a stickler for standards, just changed the behaviour of a POSIX function?
  • pluc 1 hour ago
    A+ name
  • philipwhiuk 13 minutes ago
    Magic characters are awesome.
  • cube00 50 minutes ago
    > except a lot of programs never check for NULL. they just compare whatever crypt() gives back with the stored field, hit the NULL, and crash

    > so musl (the libc under alpine) goes ok fine, crypt() just won't return NULL anymore. if it fails, it returns a single character instead.

    Considering it's been accepted that crashing if malloc returns a NULL is your fault, did musl really feel the need to accommodate bad implementations like this or is this just AI speculation?

    • red75prime 27 minutes ago
      "unfortunately, a large portion of programs which call crypt are not prepared for its failure and do not check that the return value is non-null before using it. thus, always "succeeding" but giving an unmatchable hash is reportedly a better behavior than failing on error." [1]

      [1] https://git.musl-libc.org/cgit/musl/commit/?id=b3c4cc121f70f...

      • afc 4 minutes ago
        Such a questionable decision! "Rather than let a bug in a caller (not handling the valid null output and thus crashing) surface, let's just silence it and pretend that the caller is correct! A potential clash in some situations (resulting in this vulnerability) is better than a crash!"

        Maybe I should update my plea to fail loudly (https://alejo.ch/3gk) to list this as an example.

    • Good4boothee 28 minutes ago
      > did musl really feel the need to accommodate bad implementations like this

      I don't know about this specific case but in general? Yes, totally. No one is going to fix all existing software that depends on libs behaving exactly as glibc, you have to accept some trade-offs. Either your new implementation stops being perfectly simple and clean, or no one uses it.

  • bombcar 1 hour ago
    The real name of this is sshole - the is the "star" of the show, after all.
    • yreg 56 minutes ago
      *sshole, the * is the star of the show

      You can use \ to escape formatting.

  • stogot 26 minutes ago
    Of all the named vulnerabilities, I appreciate the history lesson and screenshots of how it got there
  • gosen 52 minutes ago
    I really like creativity in the name, the way website built and the content

    "tl;dr" was a bit of a downgrade though, but that's fine

    it's a nice way to promote the company behind it

  • jdw64 48 minutes ago
    I liked that this site explained the vulnerability in an easy-to-understand way.
    • ordu 23 minutes ago
      I can't understand it. All this scrolling and pictures are distracting me, can't concentrate really.
      • vavkamil 1 minute ago
        Yep, scrolling through my phone and reading slowly to understand. I'm seeing distracting animations below what I'm reading. And when I go to them, there is no way to restart them. So it completely misses the point.
      • jdw64 18 minutes ago
        I think it varies from person to person. Since I'm kind of from the TikTok generation, I don't have much trouble reading this kind of animation, but some people prefer static sites. That's just how it is.

        I also found scroll-triggered animations hard to read at first, but these days a lot of sites use them, so I've gotten used to them.

  • lclc 39 minutes ago
    One more reason to build your (own) Docker images on 'FROM scratch' (basically nothing).
    • blueflow 36 minutes ago
      No, the Alpine containers don't come with sshd preinstalled. You'd have to manually install via dockerfile and leave it unconfigured.
    • Good4boothee 26 minutes ago
      No one runs sshd in containers, at least I hope so. What would even be the point when you have docker/kubectl commands available?
  • henry700 36 minutes ago
    at this point my only reaction is "are you fucking kidding me"
  • rvz 1 hour ago
  • ChrisRR 39 minutes ago
    Can we just have a site with the text and images without the awkward scrolling crap? Hijacking basic features is an instant click away from sites for me

    Edit: It seems to work fine on mobile. I'm not sure why the scrolling behaviour was added on the desktop version of the site

  • sneela 46 minutes ago
    Yet another clankered finding creating a clankered website with clankered explanations. To be fair, this one's a lot better than the other clankered equivalents, but I wonder whether these people even know enough about their bug to have their own write-up?

    Also, what's with this damn trend of typing in lowercase only? Why is this a thing?

    > oh did i say "i"? sorry. i had agent swarms. a lot of them. let's not get into it

    Still a cool finding... it's just the communication is becoming a lot worse these days - I want to understand the findings please, not be impressed by your webpage! Biggest gripe in recent memory is https://github.com/xoreaxeaxeax/skitter-creek-bath-salts

    • BugsJustFindMe 30 minutes ago
      > Also, what's with this damn trend of typing in lowercase only?

      Anticapitalism.

  • oefrha 26 minutes ago
    This is a super duper annoying site for people who just want to know if their systems are vulnerable, after patching like a dozen critical vulnerabilities in other software over the last week and are almost at the breaking point of resigning.

    Can we have a “don’t treat me like five/toddler” / “idgaf about the explanation” quick link to a section for adults who need to patch systems?

    (And if your reaction is “just scroll down, stupid”, I’m happy to report that with the scroll jacking, I scroll not enough / past the critical sections nine out of ten times.)

    Edit: You may want to read https://sshhole.com/#exposure.

    • jamal-kumar 1 minute ago
      It's people like you I fire with glee
    • rmunn 18 minutes ago
      Thanks for mentioning that before I tried to scroll down. Forewarned, I was able to click on the "2026" link once the left-handed "scrollbar" (not the right word but I can't figure out what the right word should be) appeared, which let me jump past most of the verbiage and get to the "are you affected?" section just a couple pages later.