Screen Sharing in FireFox

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8Geee
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Joined: Mon 12 May 2008, 11:29
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Screen Sharing in FireFox

#1 Post by 8Geee »

Not sure how long this one has been around but in testing and tweaking 45.8ESR for updated eee-spins, I found this in about config

media.getusermedia.screensharing.enabled;false
media.getusermedia.screensharing.allowed_domains;

except line 1 was default true, and line 2 had all sorts of domain-names.

Posted for those of us not needing this function. It has potential for serious abuse, thus posted here.

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8Geee
Linux user #498913 "Some people need to reimagine their thinking."
"Zuckerberg: a large city inhabited by mentally challenged people."

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Burn_IT
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#2 Post by Burn_IT »

The list is redundant now in later versions.
Screen sharing is likely only needed to allow external help with your machine.
"Just think of it as leaving early to avoid the rush" - T Pratchett

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8Geee
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#3 Post by 8Geee »

IIRC, its also used by remote access apps like Go2MyPC etc. Some are pricey subscriptions, but some are free for personal use.

Regards
8Geee
Linux user #498913 "Some people need to reimagine their thinking."
"Zuckerberg: a large city inhabited by mentally challenged people."

Sailor Enceladus
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#4 Post by Sailor Enceladus »

I checked Firefox 52.1esr and it is set to true there too. According to here, that list is now useless/ignored though (?):
https://wiki.mozilla.org/Screensharing
IMPORTANT: The Screensharing whitelist is no longer needed to share your screen or windows starting Firefox 52 (April). Please let us know if you find any problems!
I was using something called rabb.it where you share your screen (and audio) for people, I wonder if that's the same thing.

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souleau
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#5 Post by souleau »

Firefox 44 also has this set to true by default, plus the website list.

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greengeek
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#6 Post by greengeek »

If anyone has concerns about the ability of the browser to screenshare (either explicitly via that config list) or automatically as enabled in newer browsers it may be worth investigating exactly what webRTC enabled browsers are capable of.

It appears to me that modern browsers have an inbuilt ability to share the screen, and webcam, and microphone on demand. The question is - how much security is built around those functions and can we feel safe that we have total control over them?

When I use Chrome I see various funny messages from other programmes suggesting that the browser has already taken control over various functions of my sound card - without it ever having asked my permission to do so.

Don't know about more recent Firefox versions as I am still using 17.0ESR

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