793121 - (CVE-2012-4195) nsLocation::CheckURL can use the wrong principal

Status: RESOLVED FIXED

(Core :: Security, defect)

Description

[moz_bug_r_a4]

This is a regression from bug 754202. (fx16,17,18 are affected.)

When a chrome code calls an untrusted function via CrossCompartmentWrapper/WaiveXrayWrapper, GetSubjectPrincipal returns a content principal, but GetPrincipalAndFrame returns the system principal.  nsLocation::CheckURL gets an owner principal by calling GetCxSubjectPrincipalAndFrame, which calls GetPrincipalAndFrame.  

By using this bug, content can perform an XSS attack, and if there is an extension that exposes a chrome window to content, content can run arbitrary code with chrome privileges.

Comment 1

[moz_bug_r_a4]

Attachment: testcase 1 - XSS

This tries to get cookies for www.mozilla.org.

Comment 2

[moz_bug_r_a4]

Attachment: testcase 2 - arbitrary code execution with Error Console

Comment 3

[Bobby Holley (:bholley)]

I decided to do this work over in public over in bug 797204, since the security issue at hand is non-obvious.

Comment 4

[Lukas Blakk [:lsblakk] use ?needinfo]

We've already gone to build with beta6 so the window on 16 landings has closed. Wontfixing for 16.

Comment 5

[Daniel Veditz [:dveditz]]

fixed on trunk in bug 797204
https://hg.mozilla.org/mozilla-central/rev/238f3986fe71
https://hg.mozilla.org/mozilla-central/rev/c5760a66bfcf
https://hg.mozilla.org/mozilla-central/rev/798a316ebfaa
https://hg.mozilla.org/mozilla-central/rev/94317b3cb4d5

Comment 6

[Daniel Veditz [:dveditz]]

Re-noming for 16 in case we consider this fix for a 16.0.2 "location cleanup" chemspill. In light of bug 801305 though it might be incomplete and/or regression prone; Firefox 17 might be as early as we want to push it.

Comment 7

[Lukas Blakk [:lsblakk] use ?needinfo]

bug 797204 has the uplift approvals, just need them to land on branches.

Comment 8

[Bobby Holley (:bholley)]

(In reply to Lukas Blakk [:lsblakk] from comment #7)
> bug 797204 has the uplift approvals, just need them to land on branches.

Unfortunately we determined that bug 797204 doesn't fix this bug. I've got more targeted patches over in bug 801305.

Comment 9

[Alex Keybl [:akeybl]]

(In reply to Bobby Holley (:bholley) from comment #8)
> (In reply to Lukas Blakk [:lsblakk] from comment #7)
> > bug 797204 has the uplift approvals, just need them to land on branches.
> 
> Unfortunately we determined that bug 797204 doesn't fix this bug. I've got
> more targeted patches over in bug 801305.

Can we mark FF17-19 as fixed now that bug 801305 has landed?

Comment 10

[Daniel Veditz [:dveditz]]

Attachment: Testcase 1 -- XSS (updated)

The original XSS testcase doesn't work because www.mozilla.org now has an X-Frame-Options header to prevent framing. This is functionally equivalent, at least until blog.mozilla.org does the same thing.

Comment 11

[Daniel Veditz [:dveditz]]

I'm downgrading to sec-high because it's not at the moment a known drive-by exploit. addons are already on dangerous ground using unwrapped DOM objects and should not be injecting content that way.

Comment 12

[Daniel Veditz [:dveditz]]

bug 801305 hadn't been checked in on branches when comment 9 was asked, but it has now and I've verified the fix in Nightly and Aurora.