cross-posted from: https://sh.itjust.works/post/923025

lemmy.world is a victim of an XSS attack right now and the hacker simply injected a JavaScript redirection into the sidebar.

It appears the Lemmy backend does not escape HTML in the main sidebar. Not sure if this is also true for community sidebars.

  • Chay
    link
    fedilink
    English
    arrow-up
    2
    ·
    1 year ago

    I think it depends, I for one have no idea what other modifications the Lemmygrad team has done to their website, if it’s running stock Lemmy then it’s a chance it might be exploited. From what I’m reading in that thread, the whole Markdown parser doesn’t sanitize things, like this could get interpreted as valid code and run in the user’s browser. The attack on lemmy.world seems just to steal cookies in your browser, thus login credentials, or even more if your browser doesn’t separate cookies. For the moment I would suggest more vigilance when clicking unknown links and such

    • ImOnADiet
      link
      fedilink
      English
      arrow-up
      3
      ·
      1 year ago

      her claim was that “Lemmygrad doesn’t allow HTML in its markdown parser”

      • Chay
        link
        fedilink
        English
        arrow-up
        2
        ·
        1 year ago

        Well yeah we should be fine if there’s not another exploit, I see Hexbear and other instances have already patched it and resetted the login tokens