Edit: A user found the issue and clarified its an issue with the website using placeholder pointing to localhost, probably when developing. This old post title has been changed from "An accounts profile causes a localhost Port Scan on Firefox" to "A website causes a localhost Port Scan on Firefox" to reflect the new found information. Solution here (a reply in this post): https://lemmy.ml/post/51842257/27445377

Post in question: https://lemmy.ml/post/51833596 which links to the actual "problematic" webpage: https://radicle.dev/guides/user

A users account / profile post causes a localhost Port Scan (attempt) on my Firefox, when I either open the page or even when posts of the account are listed in my Subscribed feed view. I just noticed this because I have an addon installed that blocks and notifies me about this: https://addons.mozilla.org/en-US/firefox/addon/port-authority/ The addon lists port 3000.

Is this something to be concerned about?

Edit: Removed the link from this Post URL, so it does not cause the Port Scan to others I was reporting here.

Enter the URL on VirusTotal and share the link to VirusTotal here.

https://www.virustotal.com/gui/url-analysis/u-995b96b122733d286a2f231e294feab4ec6250fcfa100ea611bdacda37dbb251-8ab6995a Last analysis was 25 minutes ago (for context, that is after my post here), I started a new one. Nothing seems to be known and detected. Does VirusTotal do a HTML/CSS scan only without executing the JavaScript? Because the Port Scan is dynamically done through JavaScript.

Looks like a user found the culprit: https://lemmy.ml/post/51833596/27444526

<meta property="og:image" content="http://localhost:3000/assets/images/og-card.png">
<meta name="twitter:image" content="http://localhost:3000/assets/images/og-card.png">

copying what i wrote to here:

the website linked in the OP is misconfigured and never replaced/removed the placeholders.

you can find the intended image here:

radicle.dev has a misconfigured sharing thumbnail. the reason you get the Local Network Access warning on both the post and the user's profile is because their post is visible from both pages, and it tries to load the thumbnail which is addressed to localhost.

Thanks I will update the post to reflect that information. Edit: When I opened the webpage, I did not get any warning, so I thought its an issue on Lemmy.