[tor-bugs] #27848 [Applications/Tor Browser]: Cloudflare consistently displays captcha for TorBrowser 8.0.1 but not for 8.0.0

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#27848: Cloudflare consistently displays captcha for TorBrowser 8.0.1 but not for
8.0.0
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 Reporter:  cypherpunks_reply         |          Owner:  tbb-team
     Type:  defect                    |         Status:  new
 Priority:  Medium                    |      Milestone:
Component:  Applications/Tor Browser  |        Version:
 Severity:  Normal                    |     Resolution:
 Keywords:                            |  Actual Points:
Parent ID:                            |         Points:
 Reviewer:                            |        Sponsor:
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Comment (by cypherpunks_reply):

 mitmflare does detect tor browser, this is not new (it has nothing to do
 with the mentioned alt-svc-based onion redirections), it exists since at
 least tor browser 7.x

 and it's not a trivial detection (like just the value of request headers),
 their fingerprint includes much more, it likely goes to the tls level,
 possibly to the tcp level

 if anyone knows details, I want to read them, thanks

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/27848#comment:2>
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