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(URGENT) Lemmy has an XSS vulnerability in the tagline, the sidebar and in the legal information field - sh.itjust.works
sh.itjust.works# DO NOT OPEN THE “LEGAL” PAGE — 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.
[https://sh.itjust.works/pictrs/image/707c0f16-3d5c-4888-b865-34228d968ee6.png]
EDIT: the exploit is also in the tagline that appears on top of the main feed
for status updates, like the following one for SDF Chatter:
[https://sh.itjust.works/pictrs/image/2dc8838f-4611-4b62-92d2-ab45d7b1c560.png]
[https://sh.itjust.works/pictrs/image/9195ec9c-166e-4190-a991-26d218089602.png]
EDIT 2: The legal information field also has that exploit, so that when you go
to the “Legal” page it shows the HTML unescaped, but fortunately (for now) he’s
using double-quotes. "legal_information":" ![\"
onload=\"if(localStorage.getItem(`h`) != `true`){document.body.innerHTML =
`\u003Ch1\u003ESite has been seized by Reddit for copyright
infringment\u003C\u002Fh1\u003E`; setTimeout(() =\u003E {window.location.href =
`https:\u002F\u002Flemmy.world\u002Fpictrs\u002Fimage\u002F7aa772b7-9416-45d1-805b-36ec21be9f66.mp4`},
10000)}\"](https:\u002F\u002Flemmy.world\u002Fpictrs\u002Fimage\u002F66ca36df-4ada-47b3-9169-01870d8fb0ac.png
\"lw\")
Ma non c’e un qualche aggiornamento con patch di sicurezza? Feddit ha risolto la vulnerabilità?
Nell’ultima mezz’ora c’è stata ancora attività su quella issue su GitHub (tutt’ora aperta) e sembra che il problema riguardi le custom emoji, non la sidebar. Il bug riguarda solo il frontend web e con una validazione lato client dovrebbe essere risolto, tuttavia non vedo ancora nuove versioni della lemmy-ui. C’è però una procedura di recovery documentata qualora dovessero verificarsi problemi.
AGGIORNAMENTO- Ho cancellato e reinserito l’account dalla app dopo aver resettato la password (da email). Sembra funzionare a dovere adesso👍