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.

  • Greg Clarke@lemmy.ca
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    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
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      1 year ago

      yup pretty sure

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

      😉

    • delial@lemmy.sdf.org
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      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
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        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
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          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.