ZDI-11-223: Mozilla Firefox SVGPathSegList.replaceItem Remote Code Execution Vulnerability

http://www.zerodayinitiative.com/advisories/ZDI-11-223

June 21, 2011

-- CVE ID:
CVE-2011-0083

-- CVSS:
7.5, (AV:N/AC:L/Au:N/C:P/I:P/A:P)

-- Affected Vendors:
Mozilla

-- Affected Products:
Mozilla Firefox

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TippingPoint IPS customers have been protected against this
vulnerability by Digital Vaccine protection filter ID 11214. 
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-- Vulnerability Details:
This vulnerability allows remote attackers to execute arbitrary code on
vulnerable installations of Mozilla Firefox. User interaction is
required to exploit this vulnerability in that the target must visit a
malicious page or open a malicious file.

The specific flaw exists within the code responsible for parsing SVG
path segment objects. The function nsSVGPathSegList::ReplaceItem() does
not account for deletion of the segment object list within a user
defined DOMAttrModified EventListener. Code within
nsSVGPathSegList::ReplaceItem() references the segment list without
verifying that it was not deleted in the aforementioned callback. This
can be abused to create a dangling reference which can be leveraged to
execute arbitrary code within the context of the browser.

-- Vendor Response:
Mozilla has issued an update to correct this vulnerability. More
details can be found at:

http://www.mozilla.org/security/announce/2011/mfsa2011-23.html

-- Disclosure Timeline:
2011-04-04 - Vulnerability reported to vendor
2011-06-21 - Coordinated public release of advisory

-- Credit:
This vulnerability was discovered by:
    * regenrecht

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