[tor-bugs] #8864 [Tor]: Hidden service: Suddenly the service does not respond to new connections (INTRODUCE2 cell on intro circ with no corresponding rend_intro_point_t)

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#8864: Hidden service: Suddenly the service does not respond to new connections
(INTRODUCE2 cell on intro circ with no corresponding rend_intro_point_t)
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     Reporter:  reiam   |      Owner:
         Type:  defect  |     Status:  needs_review
     Priority:  normal  |  Milestone:  Tor: 0.2.???
    Component:  Tor     |    Version:  Tor: 0.2.3.25
   Resolution:          |   Keywords:  tor-hs 023-backport 025-triaged
Actual Points:          |  Parent ID:
       Points:          |
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Comment (by asn):

 Some quick thoughts:

 Assuming that the patch goes in, I guess the attack here is "You want to
 find when an HS fetches a new consensus. Monitor all its IPs, find the
 first time one of them is not in the consensus. At that time, keep on
 hitting the HS through that IP, and see when it stops responding. That's
 the point it probably loaded the new consensus.".

 It's plausible I guess, but I can't find any plausible attacks that it
 allows. Maybe we are worrying that it might enable traffic confirmation
 attacks ("That HS caused this much traffic at exactly THEN")?
 However, one might argue that that's already easy with hidden sercices
 anyway since you can send (and receive) traffic to/from it whenever you
 want.

 More thinking required?

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/8864#comment:24>
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