86028 - can redefine focus() and other allAccess functions at another domain

Status: RESOLVED FIXED

(Core :: Security: CAPS, defect, P2)

Description

[Jesse Ruderman]

I can redefine focus() and several other functions on pages at another domain.  
I should only be able to call these functions, not redefine them.  The 
redefined function runs with the principal of the attacker, and these functions 
aren't called with interesting parameters, so this isn't a huge security hole.

Here's the line form all.js:
  pref("capability.policy.default.Window.focus", "allAccess");

I think this should be
  pref("capability.policy.default.Window.focus.get", "allAccess");
but I couldn't figure out how to test that change.

Comment 1

[Jesse Ruderman]

Attachment: demo using blur()

Comment 2

[Mitchell Stoltz (not reading bugmail)]

Target is now 0.9.4, Priority P2.

Comment 3

[Jesse Ruderman]

Similar to bug 77503, possible to set window.toString for another domain.

Comment 4

[Mitchell Stoltz (not reading bugmail)]

Not critical for 0.9.4, moving to 0.9.5.

Comment 5

[Mitchell Stoltz (not reading bugmail)]

This appears to be fixed now, but the behavior is a little surprising. When I
call x.focus(), where x is a window at another domain, XPConnect calls the
security manager regarding a call to Window.focus(). When I attempt to redefine
x.focus(), the DOM helper at nsDOMClassInfo calls the AddProperty security
check, and that's what gets rejected. 

I think this is the correct behavior. Jesse, can you verify that this bug is
fixed and maybe try some variations?

Comment 6

[bsharma]

Verified on 2001-10-10-branch build on WinNT

I get the following error on the Js console when I run the attached test case

Error: uncaught exception: Permission denied to set property Window.scriptglobals

Comment 7

[Mitchell Stoltz (not reading bugmail)]

This bug appears to have re-emerged.

Comment 8

[Daniel Veditz [:dveditz]]

dang, fell through the cracks!

Comment 9

[Johnny Stenback (:jst)]

Seems like Jesse's suggestion works as expected, patch coming up.

Comment 10

[Johnny Stenback (:jst)]

Attachment: Only allow getting allAccess functions across domains, don't allow setting them.

Comment 11

[Christopher Aillon (sabbatical, not receiving bugmail)]

Comment on attachment 144693 [details] [diff] [review]
Only allow getting allAccess functions across domains, don't allow setting them.

What is
http://lxr.mozilla.org/mozilla/source/calendar/sunbird/app/profile/all.js and
does that need the same changes?  r=caillon once you figure that out.

Comment 12

[Johnny Stenback (:jst)]

Hmm, messed up. Yeah, that should be updated as well, but I think I'd rather
file a bug on Sunbird to not duplicate all.js, since that's a mantenance
nightmare, something we really really don't want with files like this. There are
better ways. I filed bug 238569 on sunbird to not use a copy of all.js. But for
now, I don't think we need to worry about that.

Comment 13

[Christopher Aillon (sabbatical, not receiving bugmail)]

Fair enough.

Comment 14

[Daniel Veditz [:dveditz]]

What am I missing? If I apply the patch the "demo using blur()" testcase still
shows the bug for me.

Comment 15

[Johnny Stenback (:jst)]

Hmm, is your Mozilla build finding other prefs that override what you're
setting? Does about:config reflect what you've changed in your all.js pref file?

Comment 16

[Johnny Stenback (:jst)]

Hmm, I guess we don't show these prefs in about:config at all, so that's not
very helpful.

I double checked that this does indeed fix the problem for me, I tried in a
SeaMonkey debug tree, and in a Firefox release tree, problem solved in both
cases. I now get an exception when trying to set window.blur across domains
(using the attached testcase).

Comment 17

[Johnny Stenback (:jst)]

Those trees were both WinXP builds, tested on Linux (Firefox) as well.

Comment 18

[Daniel Veditz [:dveditz]]

Comment on attachment 144693 [details] [diff] [review]
Only allow getting allAccess functions across domains, don't allow setting them.

My bad -- misled by the all.js that's still installed under defaults\pref. The
active settings from from the [GRE]\greprefs dir. Works just fine

sr=dveditz
a=dveditz for 1.7

Comment 19

[Johnny Stenback (:jst)]

Fix checked in, closing bug.

Comment 20

[Hiro]

Hard coding of the following pref is carried out in Camino.
Isn't this influenced?
  capability.policy.default.Window.blur
  capability.policy.default.Window.close
  capability.policy.default.Window.focus
http://lxr.mozilla.org/mozilla/source/camino/src/preferences/PreferenceManager.mm#329
(It may still be in other places.)

Comment 21

[Hiro]

pinkerton-san,
Please check, "capability.policy.default.*"

Comment 22

[Christopher Aillon (sabbatical, not receiving bugmail)]

[e-mail], camino is not setting default prefs, but clearing user set
values.  Look at the code.  By doing so, it is setting everything to the default
which is in all.js.   If for whatever reason camino does not have this all.js,
then the default values would be "sameOrigin" and that is not succeptible to
this bug.

Comment 23

[[e-mail]]

(In reply to comment #16)
>Hmm, I guess we don't show these prefs in about:config at all, so that's not
>very helpful.
That behaviour predates my involvement with about:config so I just carried it
forward but perhaps you'd like a pref to show those prefs or something ;-)

Comment 24

[Johnny Stenback (:jst)]

(In reply to comment #23)
> (In reply to comment #16)
> >Hmm, I guess we don't show these prefs in about:config at all, so that's not
> >very helpful.
> That behaviour predates my involvement with about:config so I just carried it
> forward but perhaps you'd like a pref to show those prefs or something ;-)

I'm fine either way. I don't want people to mess with those pefs too much, so
there's some value in not showing them to the users of about:config...

Comment 25

[Daniel Veditz [:dveditz]]

Adding Jon Granrose to CC list to help round up QA resources for verification

Comment 26

[Christopher Aillon (sabbatical, not receiving bugmail)]

Comment on attachment 144693 [details] [diff] [review]
Only allow getting allAccess functions across domains, don't allow setting them.

a=blizzard