[tbb-bugs] #31587 [Applications/Tor Browser]: Conflicting metadata which could lead to fingerprinting

[Tor Bug Tracker & Wiki]

#31587: Conflicting metadata which could lead to fingerprinting
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 Reporter:  bigsteve1337  |          Owner:  tbb-team
     Type:  defect        |         Status:  new
 Priority:  Medium        |      Component:  Applications/Tor Browser
  Version:                |       Severity:  Normal
 Keywords:                |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:
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 Tor Browser Version: 60.8.0esr
 OS: MacOS Mojave

 When I go to http://whatsmyos.com/ it tells me I am using Windows 7, which
 is good.

 However, if I go to https://brave.com it figures out that I am on MacOS
 and automatically defaults to the MacOS download.

 This is conflicting metadata and is prone to fingerprinting (which is
 exactly what the fake Windows 7 info was trying to avoid).

 After checking on panopticlick, I realized the conflict comes from:

 User Agent: Mozilla/5.0 (Windows NT 6.1; rv:60.0) Gecko/20100101
 Firefox/60.0

 Platform:   MacIntel

 Perhaps it's as easy as making the 'Platform' HTTP header just match the
 Windows user agent?

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/31587>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
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