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[–] 7 points 23 hours ago (3 children)
  • [–] 1 point 16 hours ago (2 children)

    In some "passwordless" configurations - in other words: working as designed.

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  • [–] 3 points 15 hours ago (1 child)

    Passwordless is intended to prevent accessing an account using a password, so not as designed.

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  • [–] 2 points 15 hours ago

    Ah, that kind of passwordless - thanks for the correction.

    The passwordless I always use is the one where you turn on the machine and have access to the desktop without entering credentials.

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  • 80 comments in c/technology@lemmy.world view that post
    [–] 87 points 1 day ago (16 children)

    The only time I ever exposed my SSH port to the WAN, I got about 750 connection attempts from China and 250 attemps from Russia per hour.

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  • [–] 23 points 20 hours ago* (8 children)

    yeah, while reading this i was going "What maniac exposes SSH to WAN anyway...?" the whole time. I fail to see any reason or point that can be justified exposing SSH to WAN.

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  • [–] 27 points 18 hours ago (6 children)

    I used to have a synology NAS that would sleep of death itself. Synology support asked me to port forward SSH to the open internet and set no password so they could pull logs over the next few weeks.

    Yes, it was legit synology support not a scammer.

    No, I haven’t bought synology ever again.

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  • [–] 5 points 15 hours ago (5 children)
  • [–] 4 points 14 hours ago (3 children)

    Not the person you responded to, but I'll give my unsolicited advice: I switched to Unifi NAS. QNAP has had a lot of security nightmares, and a bad habit of EOLing devices.

    The best option might actually be using an old workstation and going with something like TrueNAS, but I enjoy the convenience of a purpose built box.

    One big difference between Unifi NAS and something like QNAP or Synology, is that the Unifi NAS only does NAS work, it doesn't run containers or "apps". You need separate compute if you want to run containers.

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  • [–] 2 points 13 hours ago

    Unifi actually sounds better. I'm the same and want my NAS to be optimized by someone smarter than me. I've been using qnap and don't really care for half the crap they offer. They're not as enshittified as Synology, but they're getting there.

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  • [–] 10 points 18 hours ago*

    Any VPS provider just gives you an SSH IP and port. So that's the default state, until you do something else, which I imagine many don't, since key based authentication was always considered secure.

    So I don't know the reason, but that's the standard practice with most providers, like Digital Ocean or Linode or whatever. You can call them maniacs but you shouldn't be surprised at something so ubiquitous.

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  • [–] 9 points 14 hours ago (2 children)

    Yet some people will still say with a straight face "tHeRe iS nO hYbRiD wAr!1!1"

    Not in Ba Sing Se at least...

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  • [–] 53 points 21 hours ago (2 children)

    tldr: disable password auth in ssh.

    Also name misses the point I think, it's a musl-hole.

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  • [–] 39 points 1 day ago (5 children)

    Given this is a vuln when entering the password, just turn off password auth and use ssh keys only. It's what you should be doing anyway.

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  • [–] 3 points 18 hours ago

    Easier said than done.

    If you have to support the sort of user that barely managed to download a copy of putty a few years ago and kept using this, then walking them through key generation and use is a nightmare.

    One could fairly argue that maybe such people shouldn't have access to a system, but it is a reality.

    Of course the likelihood that a system using musl is something that class of user would be accessing is lower.

    Maybe now that ssh is generally "just there" for Windows users, you can more easily work with them to generate a key, or give them a zip file to make them have a key in a standard way. But the interaction of ssh and windows file security can be... Interesting, though mostly an issue on the ash server side.

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  • [–] 15 points 23 hours ago* (2 children)

    The vuln is specifically for key-based accounts:

    Second, the target system account must be configured to be passwordless. Passwordless accounts are commonly used for accounts that use certificate-based authentication.

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  • [–] 16 points 21 hours ago

    "passwordless" here means that the account doesn't have a password. What the person you're replying to means is that password authentication should be completely disabled in the SSH config, as that's the only way to exploit this issue.

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  • [–] 17 points 23 hours ago

    But passwords need to be enabled for SSH. You must submit a faulty password of a specific kind, and the SSH server misinterprets it for passwordless accounts, which means the server must be configured to allow you to attempt a password.

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  • [–] 47 points 1 day ago* (last edited 1 day ago) (1 child)
  • [–] 65 points 1 day ago (17 children)

    Can they please take a break from having vulnerabilities

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  • [–] 57 points 1 day ago (16 children)

    nah, find and fix as many as possible.

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  • [–] 58 points 1 day ago (15 children)

    It seems like the pattern emerging is that AI is great at finding these obscure vulnerabilities that are only exploitable on very particular systems with very particular, non-typical configurations, and only on nights where unicorns fart candycorn.

    Sure, fix them, but the hype is too much. Also, disable password auth on SSH already. Jesus. Keys arnt that hard.

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  • [–] 19 points 1 day ago (2 children)

    I agree about the AI, but desktop Linux has never been under haxxor pressure the same way windows or apple has. I also think the newer parts of the userbase are less technical than even ten years ago. Previously undocumented bugs found and squashed is great for everyone.

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  • [–] 16 points 1 day ago (6 children)

    More like AI is much faster at finding obscure vulnerabilities, because it doesn't get tired of digging into the mind-numbing details of human-generated spaghetti code. Give a human the same kind of task, and they would die of boredom 12 hours into it.

    We're entering an age where AI is quickly cleaning up the stupid security holes that have been created by decades of human mistakes, and will continue to be this way until increased AI security reviews will become more standard. The tribals wielding spears will continue to get shot by superior firepower until they adapt to the same weapons and protection themselves.

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  • [–] 4 points 16 hours ago (2 children)

    "Cleaning up" seems a little generous. It's finding them, but someone still has to patch them.

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  • [–] 1 point 6 hours ago (1 child)

    Most vulnerability patches are a few lines of code. Finding it is the hard part.

    Even then, the AI session that found it probably already has a solution to fix it.

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  • [–] 5 points 23 hours ago

    Yeah and this isn’t a new paradigm, in the sense that tools to find exploits have gotten better repeatedly and allowed those with enough knowledge to use the tools to find them, regardless of if they could manually craft the exploit themselves. There’s a multitude of bug bounties that have been claimed by those who knew how to let a reverse engineering tool like ghidra hammer away at something with variation for long enough. And the models are capable of novel exploits on their own, but generally they are just doing the same, hammering ghidra with an MCP at accelerated scale. So “only ai would have found this bug” is technically untrue and moot.

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  • [–] 2 points 18 hours ago (1 child)

    This example demonstrates my point though. It requires an extremely unusual system configuration that may or may not even exist in the real world it is so unusual. AI doesnt get tired, like you said, but its not about spaghetti code (both musl and openssh are gold-standard opposite of spaghetti code), its about trying every possible software combination in ways a human wouldnt bother.

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  • [–] 1 point 6 hours ago

    It requires an extremely unusual system configuration that may or may not even exist in the real world it is so unusual.

    You have to remember that the same AI agents finding the code are also able to exploit the code. So, if it's some extremely rare race condition requiring some convoluted pattern, it's still easy to exploit.

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  • [–] -4 points 1 day ago (4 children)

    This particular vulnerability is precisely about logins with key. Using password login renders this vulnerability useless.

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  • [–] 17 points 1 day ago (2 children)

    Using password login renders this vulnerability useless.

    This isn't the case, though I can see how the article could lead you to believe that.

    It's directly based on password rather than key input. The entire vulnerability is that typing a password longer than 256 characters automatically defaults to crypt() outputting the * character instead of a normal password hash, which is coincidentally the same default character used as the "hash" (not actually a value you could get from a normal hash, intended to be impossible to get from any normal password for that reason) for the built-in daemon account.

    When the Ars Technica article says "Second, the target system account must be configured to be passwordless", what they mean is the default daemon account, which has a hash set to * by default, and thus wouldn't normally be accessible via any hashed password... unless you happen to find out that the system chooses to not make a hash, and just send * if you type more than 256 characters.

    Look at https://sshhole.com/ if you want the details.

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  • [–] 3 points 21 hours ago

    Technically they're correct though, in a way. If every account has a password, the system isn't vulnerable.

    You're also not vulnerable if you use two factor auth, because all 2FA modules require PAM, whereas this vulnerability only exists when PAM is disabled or not installed.

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  • [–] 4 points 18 hours ago

    Other way around. This requires a passwordless account configured with sha256 or sha512 password hash, musl system with openssh installed, no PAM, and password authentication allowed:

    When logging into a passwordless account, the attacker can gain access by inputting more than 256 characters in the password field.

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  • [–] 28 points 1 day ago (6 children)

    Well that sucks. IIRC a lot of my docker images are alpine based, but they'd be safe due to never having their SSH ports exposed I assume.

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  • [–] 27 points 1 day ago* (last edited 1 day ago) (5 children)

    Why would you even have an SSH server running in a Docker container (unless the purpose of the container is being a jumpbox or similar)?

    I can't emphasise it enough how much more secure you get when you use rootless, read-only containers that are limited to truly just the software you want to run and its dependencies.

    Alpine is great for dev containers, but the final container should be:

    • immutable on the app layer (any executable path needs to be read only)
    • have only the absolutely necessary GNU tooling, service management, etc. included (for most software you don't even need these tools, and why would you give an attacker who gain access to your container, an easy way to e.g. scan your network?)
    • only the data mounted, rw only if absolutely necessary (e.g. if you host a Jellyfin server, just an example, you should have the mounted media be RO, and only the config and caches be writable, mounted noexec of course)
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  • [–] 8 points 1 day ago

    While I have not done it, I could see it being appealing as it's quicker than SSHing into the parent box first for a commonly used tool. I had a direct SSH into a systemd container for a while before deciding the extra config wasn't worth it.

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  • [–] 5 points 21 hours ago* (1 child)

    Not just rootless and read-only, but distroless/chiseled too. There's no reason to have unneeded parts of an OS in your Docker containers. It should just be one app along with any libraries it needs (or just statically compile the app)

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  • [–] 12 points 18 hours ago (1 child)

    practically need to rotate logs every hour if you foolishly leave ssh open on a open network. usually a bastion with ssh listening to port 34000 or such is a good first step.

    that said the conditions for this exploit are fascinating. no pam, shadow password set to *, using a alternative to glibc. The sacrifices to be more efficient feel on par with replacing a tank's armor with paper mache and hope.

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  • [–] 12 points 20 hours ago* (last edited 20 hours ago)

    Further, OpenSSH using musl (pronounced muscle) must not use PAM (pluggable authentication modules),

    which Alpine doesn't ship by default. Maybe one or the other remote administration suite depends on it, but those are often suspectible to exploits anyway. But you don't expose either to WAN, right?

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  • [–] 8 points 1 day ago

    RIP. I am glad I just walled off my own garden from the internet. Though I dont think I ever had a need for my own stuff to have exposed ssh ports. That sounds scary before I knew about this.

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  • [–] 15 points 1 day ago (9 children)

    Most ssh ports should be accessed through a VPN anyway, not exposed directly to the internet

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  • [–] 15 points 22 hours ago (8 children)

    Are you sure the VPN server has the smaller attack surface than the SSH server?

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  • [–] 23 points 21 hours ago* (last edited 21 hours ago) (6 children)

    Wireguard and apps based on it (like Tailscale) don't respond at all unless the data is signed with the key of a configured peer (or with Tailscale, a system on your tailnet that passes the ACL). It's literally impossible for an outsider/attacker to detect with a port scan since it just ignores unauthenticated packets.

    The Wireguard codebase is also extremely small. The core Wireguard implementation (the version in the Linux kernel) is around 5,000 lines long, so an experienced developer can read through all the code if they dedicate a day or two to it, and understand how it works.

    For comparison, OpenVPN is around 70,000 lines of code and OpenSSH is around 150,000 lines of code. There's a huge number of features in SSH!

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  • [–] 6 points 21 hours ago

    That is a convincing argument. I wasn't thinking of wireguard, but it makes sense that it's quite small and focused, being in the kernel.

    I'm dealing more with OpenVPN and that can be very annoying, that had me lean in the opposite direction earlier (and lets not even speak of the Cisco crap).

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  • [–] 2 points 20 hours ago (4 children)

    Why aren't there more minimal implementations like tinyssh?

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  • [–] 4 points 19 hours ago (2 children)

    Because all those extra features are really useful. You can run all sorts of things over ssh, from sophisticated file transfer to remote development and tunneling

    Ssh is remote code execution. Under any implementation, any authentication methods should be the absolute last line of defense after you've properly locked down access

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  • [–] 1 point 19 hours ago* (last edited 10 hours ago) (1 child)

    Well, yeah but more features in remote code excution = more vulnerabilities. For example sftp: you could also just run ftp over vpn for the same effect. Or just cat the file over ssh. Instead, we have one big monolith.

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  • [–] 1 point 8 hours ago

    SFTP is just FTP over SSH... Also, FTP is essentially one small step away from code execution, even on a secure network it's better to use SFTP

    SSH isn't many things, it's one connection type through which you can do many things. You can't simply cat a file over without being able to handle the throughput gracefully, otherwise you'd have to design a new layer to do exactly the same thing. The same for reading files, if it can't gracefully spit out 10k lines in a second you couldn't handle output

    And if you can do all that, why not allow VIM over the same connection? You're already going to have to manage the terminal session, why not fully reflect a terminal?

    FTP is absolutely not the answer, but a server that will conditionally serve files as well as conditionally accept uploads is far more secure. The same for everything... If you want to manage users, instead of allowing remote code execution you should use an API to perform predefined tasks

    SSH isn't meant for security or production use, it's meant for power and flexibility. It's generally deactivated by default for a reason, but it's included for a reason too. It's just really damn useful

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  • [–] 15 points 18 hours ago (5 children)

    Wait that means I have to expose a port. But I have zero exposed ports.

    This post was created by the pangolin-gang.

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  • [–] 5 points 12 hours ago (3 children)

    Meaning router port, not firewall port? I struggle to know the difference.

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  • [–] 7 points 6 hours ago (2 children)

    Some people seem to think that by not opening a port in their router, and instead opening a reverse tunnel to a VPS which has an open port, it somehow makes them more secure

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  • [–] 4 points 6 hours ago*

    Is the name of the vulnerability literally *sshole?

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  • [–] 7 points 16 hours ago

    What an aSSHole!

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  • [–] 13 points 1 day ago (4 children)

    Alpine? The one that doesn’t use glibc? Wasn’t this why they chose a different C runtime? For security. Ooops.

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  • [+] 1 point 9 hours ago*
    10 comments in c/linux@lemmy.world view that post
    [–] 30 points 23 hours ago (7 children)

    Second, the target system account must be configured to be passwordless

    Finally it pays off to use my birthday as password

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  • [–] 4 points 18 hours ago (5 children)

    Funny coincidence, I'm also using your birthday as a password!

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  • [–] 13 points 17 hours ago

    The Docker Hub base image for Alpine has more than 1 billion downloads.

    Okay sure... but most docker images that are using alpine aren't running an ssh server inside that alpine container. I can't say it's zero, because I'm sure someone is doing crazy somewhere, but I bet it's very close to zero.

    The non-docker deployments are more legitimate targets, but this number here is basically useless for actual vulnerability, in my opinion.

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  • [–] 5 points 18 hours ago*

    so keys yes, and passwords no still good?

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  • 3 comments in c/cybersecurity@infosec.pub view that post
    [–] 11 points 1 day ago (1 child)

    Sorry but that is a crap title.

    SSH will allow anyone into a Linux device as long as they can authenticate successfully.

    I get that they mean that the vulnerability bypasses the authentication, but still a shit title.

    Eh, I am probably just cranky as I just woke up.

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  • [–] 9 points 1 day ago

    No, I kinda feel ya. These glib names used to feel earned and brought levity to often serious issues. Now it feels like people are tripping over themselves to use LLMs to dig out whatever inflated 9.8 they can find and rub our faces in it.

    Such is the world, but I'm kinda done laughing for awhile (is also cranky).

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  • [–] 1 point 1 day ago*

    Luckily OpenWRT doesn’t use OpenSSH and I don’t expose it by default.

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