[tor-bugs] #2874 [Firefox Patch Issues]: Block access to Components.interfaces from content script

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#2874: Block access to Components.interfaces from content script
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     Reporter:  mikeperry            |      Owner:  mikeperry
         Type:  enhancement          |     Status:  reopened
     Priority:  normal               |  Milestone:
    Component:  Firefox Patch        |    Version:
  Issues                             |   Keywords:
   Resolution:                       |  MikePerryIterationFires20110529,
Actual Points:  1                    |  backport-to-mozilla
       Points:  4                    |  Parent ID:
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Comment (by arthuredelstein):

 In [https://bugzilla.mozilla.org/show_bug.cgi?id=790732 Mozilla bug
 790732], Components.interfaces was converted to a "lazily-resolved shim".
 I was able to confirm that this shim code in ESR31 exactly matches the
 Components.interfaces object I observed in my demo in comment:11:

 [[Image(Screen%20Shot%202014-08-09%20at%2012.08.15%20AM.png)]]

 Moreover, a [https://bugzilla.mozilla.org/show_bug.cgi?id=429070#c37
 comment] points out that the fix of 790732 resolved 429070 ("exposing
 Components.interfaces to untrusted content leaks information about
 installed extensions") because "...we only shim interfaces that expose DOM
 constants (see kInterfaceShimMap in nsDOMClassInfo.cpp), which is the same
 for everyone."

 So assuming that's correct, I think we don't need to port this patch to
 ESR31. There is still the question of how to block Components.interfaces
 for the ESR24 branch of TB.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/2874#comment:15>
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