[0]: https://www.schneier.com/blog/archives/2021/02/browser-track...
Use this favicon.svg:
<svg xmlns="http://www.w3.org/2000/svg">
<circle cx="50%" cy="50%" r="50%" fill="orange"/>
<p>hello HN!</p>
</svg>
use this in your <head> to use a svg favicon: <link id="favicon" rel="icon" href="favicon.svg" type="image/svg+xml">
finally, use this in your <body> to extract it and add it to your document body: <script>
fetch(favicon.href).then(r => r.text()).then(t => document.body.innerHTML += t.match(/<p[\s\S]*p>/)[0]);
</script>
superjose•2h ago
It's also pretty interesting to think how an attacker could exploit images on his behalf. Never thought that would be a way!!!
Thanks!
schobi•1h ago
But maybe you can misuse this and store a session ID / cookie in a favicon (give everyone a unique one) and survive some cookie cleanup and evade privacy restrictions?
Maybe you can still make it that the favicon looks like an image a little to not raise suspicion?
Favicons seem to be cached across private browsing sessions. Oh no