[tor-bugs] #15515 [Tor]: Don't allow multiple INTRODUCE1s on the same circuit

[Tor Bug Tracker & Wiki]

#15515: Don't allow multiple INTRODUCE1s on the same circuit
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     Reporter:  asn      |      Owner:
         Type:  defect   |     Status:  needs_review
     Priority:  normal   |  Milestone:  Tor: 0.2.6.x-final
    Component:  Tor      |    Version:
   Resolution:           |   Keywords:  026-backport 025-backport
Actual Points:           |  024-backport
       Points:           |  Parent ID:  #15463
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Comment (by cypherpunks):

 > reduce the logging severity of the warning message from this ticket to
 info, till 0.2.5 goes out of style.

 Upgrading can't to prevent legit client from sending second introduce1
 cell on behalf of broken or evil HS. Client do not deduplicates intro
 points when parsing and storing them and not checking for anything for
 intro point when get NAK and re-extend intro circuit.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/15515#comment:21>
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