[tor-bugs] #7430 [Tor Check]: Easy MITM against check.tpo (not SSL-related)

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#7430: Easy MITM against check.tpo (not SSL-related)
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 Reporter:  cypherpunks  |          Owner:     
     Type:  defect       |         Status:  new
 Priority:  major        |      Milestone:     
Component:  Tor Check    |        Version:     
 Keywords:               |         Parent:     
   Points:               |   Actualpoints:     
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 check.tpo is there to give users with a bad setup a fighting chance of
 getting warned when they aren't actually proxying their requests through
 the the Tor network, right?

 So it would be in the interest of a malicious network operator to make it
 seem like the broken Tor setup is just fine, filling those users with
 false confidence.

 What would stop such a malicious network operator from looking for TCP
 requests to one of the IP addresses of check.tpo and transparently
 proxying ''just those requests'' through Tor?

 Note that SSL can do nothing at all to stop that, as the content of the
 request is never inspected or modified.

 I've never seen that particular attack discussed anywhere, and it would be
 very easy to implement.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/7430>
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