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Issue 741853 link

Starred by 3 users

Issue metadata

Status: Assigned
Owner:
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: All
Pri: 2
Type: Bug



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Google Chrome Anti-XSS bypass through HTTP Parameter Pollution (HPP)

Project Member Reported by d...@google.com, Jul 12 2017

Issue description

Chrome Version: Version 60.0.3112.50 (Official Build) beta (64-bit)
OS: All

What steps will reproduce the problem?
Browse to:
http://xss.untrusted.com/xss?id=%3Cscript%20src=data:&id=alert(1)%3E%3C/script%3E

What is the expected result?
XSS blocked by the XSS auditor.

What happens instead?
XSS executes.

It appears that this is a regression of an old bug:
https://bugs.chromium.org/p/chromium/issues/detail?id=118808
Well, at least that bug is resolved "fixed" but the issue still reproduces.  (I'm biased given my work on the IE XSS filter, but...) I would say that HPP is pervasive enough that the auditor really needs to address it in order to provide a credible defense against reflected XSS.
 
Project Member

Comment 1 by sheriffbot@chromium.org, Jul 13 2017

Labels: Hotlist-Google
Components: Blink>SecurityFeature

Comment 3 by est...@chromium.org, Nov 10 2017

Labels: Hotlist-EnamelAndFriendsFixIt

Comment 4 by jochen@chromium.org, Nov 10 2017

Cc: mkwst@chromium.org
Components: -Blink>SecurityFeature Blink>SecurityFeature>XSSAuditor
Owner: tsepez@chromium.org
Status: Assigned (was: Untriaged)

Comment 5 by tsepez@chromium.org, Nov 13 2017

Labels: Needs-Feedback
Looks like this one fell through the cracks, sorry.  

Can you give me the exact reflection in the page text so to be sure we're on the same page, so to speak?  I didn't see anything returned from the example url in the original description.

Comment 6 by kkotow...@gmail.com, Nov 14 2017

It's hpp, in this case the id parameters from the GET get concatenated server side with a comma, creating a valid data: url for the script.

Comment 7 by tsepez@chromium.org, Nov 21 2017

I'm guessing you meant

  <script src=data:,alert(1)></script>

is what appears in the page. XSSAuditor is extremely sensitive to subtle changes in punctuation, which is why I asked for the exact page contents rather than an explanation.

Comment 8 by est...@chromium.org, Feb 18 2018

Labels: -Hotlist-EnamelAndFriendsFixIt

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