But now with FF 88 this option is ENABLED by default. Which means, if a PDF file contains JS it will run without any user interaction. What can possibly go wrong?
To disable this:
pdfjs.enableScripting --> false
# FF 78.10 ESR doesn't include this option and still blocks JS in PDFs by default. Just tested.
@TFG Mozilla isn't trustworthy. They've done a lot of shady shit over the last few years, including firing the only people there who were doing anything worthwhile and increasing the salaries of their executives.
"Nonprofit" should mean "the executives also don't profit," but apparently it's totally fine because "We're the *good* guys, not like our corporate mas - uh, I mean, not like Google, who definitely doesn't fund us!"
oopsy ... accidently split the toot... sorry for that.
here a reply I made about Tor-Browser:
Just noticed, the current Tor Browser has this option activated as well (at least on my phone) ... can your real IP be revealed by JS when opening a PDF file? ...I'm not an expert here.. just asking 🤔
There's a (german) vid about JS in PDFs at YT with a testing PDF (creates a popup message) mentioned here:
@TFG JS-in-PDFs get their own sandbox that's much more restrictive than JS-in-webpages, and doesn't offer zero-interaction exfiltration.
@stsp @TFG Main bug is here: https://bugzilla.mozilla.org/show_bug.cgi?id=1667973
Patch discussion is here: https://phabricator.services.mozilla.com/D91746
Upstream pdf.js discussion on preventing cross-origin information leakage is here: https://github.com/mozilla/pdf.js/issues/12744
@mhoye @TFG Unfortunately most of this is over my head since I'm not a web developer so I cannot make my own assessment. What strikes me is that the discussion seems to revolve mostly around one specific exploit. There's no explanation of how this is secured by design, apart from references to sandboxes (I'd have to research how sandboxing is implemented.)
The referenced pdf.js issue 12744 is not closed yet. Was it just forgotten or does it mean that the underlying issue hasn't been fixed yet?