Found the error Not allowed to load local resource: file:///etc/passwd while looking at infosec.pub’s communities page. There’s a community called “ignore me” that adds a few image tags trying to steal your passwd file.

You have to be extremely poorly configured for this to work, but the red flags you see should keep you on your toes for the red flags you don’t.

  • Rooster@infosec.pubOP
    link
    fedilink
    English
    arrow-up
    6
    ·
    1 year ago

    If you ran your browser as root and configured your browser to load local resources on non-local domains maybe. I think you can do that in chrome://flags but you have to explicitly list the domains allowed to do it.

    I’m hoping this is just a bad joke.

      • Greg Clarke@lemmy.ca
        link
        fedilink
        English
        arrow-up
        3
        ·
        edit-2
        1 year ago

        Are you sure? What do you get when you run $ cat /etc/passwd in terminal? Just paste the results here 😇

        Edit: to anyone reading this on the future, don’t actually do this, it was a joke

        • fox@vlemmy.net
          link
          fedilink
          English
          arrow-up
          6
          ·
          1 year ago

          yup pretty sure

          $ cat /etc/passwd
          fox:hunter2:1000:1000::/home/fox:/usr/bin/zsh
          

          😉

        • delial@lemmy.sdf.org
          link
          fedilink
          English
          arrow-up
          1
          ·
          edit-2
          1 year ago

          Since you told me not to. There isn’t a risk on most linux systems; passwords were moved to /etc/shadow a long time ago. It only leaks the names of your users and largely useless info for most attackers:

          root:x:0:0:root:/root:/bin/bash
          daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
          bin:x:2:2:bin:/bin:/usr/sbin/nologin
          sys:x:3:3:sys:/dev:/usr/sbin/nologin
          sync:x:4:65534:sync:/bin:/bin/sync
          games:x:5:60:games:/usr/games:/usr/sbin/nologin
          man:x:6:12:man:/var/cache/man:/usr/sbin/nologin
          lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin
          mail:x:8:8:mail:/var/mail:/usr/sbin/nologin
          news:x:9:9:news:/var/spool/news:/usr/sbin/nologin
          uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin
          proxy:x:13:13:proxy:/bin:/usr/sbin/nologin
          www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin
          backup:x:34:34:backup:/var/backups:/usr/sbin/nologin
          list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin
          irc:x:39:39:ircd:/run/ircd:/usr/sbin/nologin
          gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/usr/sbin/nologin
          nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
          _apt:x:100:65534::/nonexistent:/usr/sbin/nologin
          systemd-network:x:101:102:systemd Network Management,,,:/run/systemd:/usr/sbin/nologin
          systemd-resolve:x:102:103:systemd Resolver,,,:/run/systemd:/usr/sbin/nologin
          messagebus:x:999:999:System Message Bus:/:/usr/sbin/nologin
          systemd-timesync:x:998:998:systemd Time Synchronization:/:/usr/sbin/nologin
          systemd-coredump:x:997:997:systemd Core Dumper:/:/usr/sbin/nologin
          delial:x:1000:1000:,,,:/home/delial:/bin/bash
          sshd:x:103:65534::/run/sshd:/usr/sbin/nologin
          xrdp:x:104:110::/run/xrdp:/usr/sbin/nologin
          dictd:x:105:111:Dictd Server,,,:/var/lib/dictd:/usr/sbin/nologin
          nm-openvpn:x:106:112:NetworkManager OpenVPN,,,:/var/lib/openvpn/chroot:/usr/sbin/nologin
          sssd:x:107:113:SSSD system user,,,:/var/lib/sss:/usr/sbin/nologin
          
          • marvin@lemmy.sdf.org
            link
            fedilink
            English
            arrow-up
            1
            ·
            1 year ago

            Well it’s not completely useless. It offers some insights into the system. Which service accounts exists, what usernames are used.

            If an attacker finds a valid username they can then start bruteforcing the password.

            From your account list we can see you have sshd and xrdp. Do they both provide the same kind of bruteforce protection? Are there any recent exploits for either?

            • delial@lemmy.sdf.org
              link
              fedilink
              English
              arrow-up
              1
              ·
              1 year ago

              That’s why I said largely useless. An attacker can narrow down the attack surface by ignoring anything that can’t login, but that just leaves them with root and delial, and they already knew or could’ve guessed both of those pieces of information (in this context anyway).

              And as you noted when looking at the service accounts, they might be able to login or crack their way in via xrdp or sshd. So, unless you’re port-forwarding those protocols from the internet, how useful is that really? I would say largely useless. Assuming they port-scanned your public IP, they still need either an insecure config or an unpatched, remotely exploitable bug.

              That being said, you’re totally right. The average Linux user isn’t “administering” their system, so they probably aren’t following their distribution’s security mailing list, installing security patches as they’re released, and actually RTFM. It’s best for the average user to play it unbelievably safe.

              In this case, the machine isn’t actually running xrdp, and sshd doesn’t accept passwords or root logins. (Although, I need to setup knockd to protect that non-standard sshd port a bit more.) All passwords used on the system are random and longer than 32 characters. My router doesn’t port-forward to this machine, either.

              This has been an exercise of Cunningham’s Law for the benefit of those reading.

    • Farthom@lemmy.ca
      link
      fedilink
      English
      arrow-up
      0
      ·
      1 year ago

      Yeah, seems highly unlikely to ever yield any results. Even if you did manage to read a file, you have to get lucky finding a password hash in a rainbow table or the password being shit enough to crack.

      • nzodd@beehaw.org
        link
        fedilink
        English
        arrow-up
        1
        ·
        1 year ago

        Also generally the actual password (or rather its hash) is stored in /etc/shadow on most systems from the past 20 odd years.