A complete bypass of eMudhra’s 1FA OTP login system

(mastodon.catgirl.cloud)

134 points | by tensegrist 2 hours ago

14 comments

  • jttnr 1 hour ago
    Oh man, good that they are leaving the CA business.

    https://news.ycombinator.com/item?id=50195110

    • chrisjj 52 minutes ago
      That has no effect, since the'd get no such business from now.

      What's sad it they won't be taking their certs with them. Let's hope the powers up the chain conduct some deep self-refection on their part in thus fiasco.

      • dualvariable 31 minutes ago
        > Let's hope the powers up the chain conduct some deep self-refection on their part in thus fiasco.

        that almost never happens.

        stop hoping corporations grow a soul and a conscience.

        • Georgelemental 28 minutes ago
          Who said anything about soul or conscience? Getting hacked doesn't deliver value for shareholders
  • bragr 2 hours ago
    The anti AI scraping on this site doesn't work that well. I'm being served non-sense text about buttplugs. I'm human, I swear.
    • ronsor 3 minutes ago
      anti-AI scraping is often anti-privacy in practice, as any effective implementation requires invasive browser inspection to detect scrapers.
    • Muromec 2 hours ago
      That was proof of soul check and you passed
    • doubled112 51 minutes ago
      That's what comes after the verification can.
    • paimapi 1 hour ago
      that's actually the exploit, it was very physical
      • nathancahill 1 hour ago
        We're living in a South Park episode.
  • hoherd 2 hours ago
    The number the tool found was 1861. The e-mailed OTP code was 1858. What am I missing?
    • molticrystal 1 hour ago
      I noticed that as well. Figured it was a concurrency issue, and they have a follow-up message that you can see if you click on the OP of the Mastodon thread that confirmed my guess: https://mastodon.catgirl.cloud/@49016/117476097901925573

      >(yes the code is off by a few. its bc the poc is shit and to speed it up it uses 8 connections at the same time. it just stops the counter once it has a hit so its off by ~4 lmfao. you could easily fix this but cba today)

  • buildbot 2 hours ago
    So basically anyone who used this CA is screwed if someone knows your email?
    • gruez 2 hours ago
      Only if they're lazy and went with the "download key and certificate (and we'll generate the keys for you)" option. Otherwise at least how it's supposed to work is that you give a CA a certificate signing request (CSR) containing your public key, they sign it and hand back your certificate. The certificate itself doesn't contain anything sensitive, because it's the same thing that your server presents to clients. But people are lazy and might not know how to generate a csr locally, hence the aforementioned option. And of course if they're too lazy to generate a csr locally, they're probably also too lazy to keep backups, so you can be sure that eMudhra keeps a copy in case they deleted it from their downloads folder.
      • pdpi 1 hour ago
        With this exploit, what's stopping me from sending my own CSR for your domain?
  • ignatella 57 minutes ago
    I understand it in the following way:

    They put the public key into js and encrypt the body of the request. This is common practice to protect users' important data from being accessed by a proxy (in this case, Cloudflare) and is ok.

    But the real bug is that they don't rate-limit, invalidate, or protect the endpoint related to OTP checks, so it can be brute-forced, as the search space is limited.

    • ignatella 49 minutes ago
      so not sure why the author shows us the public key
  • tommica 2 hours ago
    Could someone explain this? Does this mean that it enables logging in as any account in emudhras infra?
    • cyberpunk 1 hour ago
      Yes, it’s a complete auth bypass. All you need is the email address of a user and they’ll likely sign CSRs for any domains under that account.

      It’s the end for them, I imagine.

  • cyberpunk 1 hour ago
    Don't piss off the internet, there will be consequences. I guess.
  • FLeXMurphy 2 hours ago
    Security represents less than 1% of their business.
    • lenerdenator 1 hour ago
      Aye, but it'll now represent much, much more than 1% of their corporate reputation.
    • chrisjj 50 minutes ago
      Purported security, you mean.

      Actual security, add some zeros ;)

  • trallnag 36 minutes ago
    Damn, these Mastodon accounts are a rabbit hole to get lost in
  • VladVladikoff 2 hours ago
    Hahahahha what a roast. Too funny, especially the "4 Bars" in the background of the demo.
  • gilrain 2 hours ago
    This site serves me garbage. Iocaine, I think? I use Brave.

    "If you are not [a bot], and you feel you have been served garbage by mistake, please contact the owner of the site you're visiting."

    If anyone knows another way to access the content, I'd be interested. No contact details are offered and visiting mastodon.catgirl.cloud resets my connection.

    • jwilk 37 minutes ago
      You can use https://github.com/jwilk/zygolophodon to read Mastodon posts in your terminal:

        $ zygolophodon --with-ancestors https://mastodon.catgirl.cloud/@49016/117475976434068995
      • fc417fc802 17 minutes ago
        Doesn't that also fetch the content directly? So depending on the logic of the filter it likely won't make any difference.
        • jwilk 11 minutes ago
          It uses the API, which hopefully is protected from bots less fiercely.
    • swiftcoder 1 hour ago
    • fc417fc802 19 minutes ago
      Ah yes, adopting the standard cloudflare approach. "Contact the site administrator to resolve this" but no contact details are provided.
  • baal80spam 1 hour ago
    "S" in "eMudhra stands for "Secure".
  • EQYV 2 hours ago
    Please can this not be true..
  • bigfishrunning 2 hours ago
    [flagged]
    • BigTTYGothGF 2 hours ago
      Coward.
    • _def 2 hours ago
      You should be able to open the url in any other mastodon instance where you are signed in
    • sgsjchs 2 hours ago
      weak aura
    • codeduck 2 hours ago
      so use your phone?
    • OptionOfT 2 hours ago
      There was an post about something like this a while back on lobste.rs, where some people were upset about the image that Anubis shows while it is validating your machine.
      • _def 2 hours ago
        People are so uptight, it's embarassing
      • CodinM 2 hours ago
        I mean, they do accept money to give you a version without that.