[tor-bugs] #17782 [Tor]: Relays may publish descriptors with incorrect IP address

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#17782: Relays may publish descriptors with incorrect IP address
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 Reporter:  fk      |          Owner:
     Type:  defect  |         Status:  new
 Priority:  High    |      Milestone:  Tor: 0.2.7.x-final
Component:  Tor     |        Version:  Tor: unspecified
 Severity:  Major   |     Resolution:
 Keywords:          |  Actual Points:
Parent ID:  #17811  |         Points:
  Sponsor:          |
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Changes (by teor):

 * parent:   => #17811


Comment:

 Replying to [comment:4 teor]:
 > In #17850, the following mitigation was suggested:
 > "Maybe a NATed OR should self-test its reachability before advertising
 the new IP address."
 >
 > I wonder if this would be a DoS risk because it takes relays off the
 network, but having them provide descriptors with the wrong address does
 that anyway.

 If we're going to do this, we should check:
 * IPv4 ORPort reachability
 * IPv4 DirPort reachability

 (See #6939 for IPv6 reachability tests. If we ever discover our own IPv6
 address (#5940), we should also make sure we re-do IPv6 reachability tests
 before republishing the descriptor.)

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/17782#comment:6>
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