ZDI-11-271: Mozilla Firefox appendChild DOM Tree Inconsistency Remote Code Execution Vulnerability

http://www.zerodayinitiative.com/advisories/ZDI-11-271

August 17, 2011

-- CVE ID:
CVE-2011-2378

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

-- Affected Vendors:
Mozilla

-- Affected Products:
Mozilla Firefox

-- TippingPoint(TM) IPS Customer Protection:
TippingPoint IPS customers have been protected against this
vulnerability by Digital Vaccine protection filter ID 11458. 
For further product information on the TippingPoint IPS, visit:

    http://www.tippingpoint.com

-- 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 results when .setUserData() handlers are used with an
object and .appendChild() is called within a handler. Ultimately the
import operation resulting from an .appendChild() is not guarded from
mutation, and invalid DOM trees can result. Invalid DOM trees can be
navigated resulting in dereferencing invalid pointers which can be
leveraged to execute arbitrary code in 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/mfsa2011-30.html#cve-2011-2378

-- Disclosure Timeline:
2011-04-04 - Vulnerability reported to vendor
2011-08-17 - Coordinated public release of advisory

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

-- About the Zero Day Initiative (ZDI):
Established by TippingPoint, The Zero Day Initiative (ZDI) represents 
a best-of-breed model for rewarding security researchers for responsibly
disclosing discovered vulnerabilities.

Researchers interested in getting paid for their security research
through the ZDI can find more information and sign-up at:

    http://www.zerodayinitiative.com

The ZDI is unique in how the acquired vulnerability information is
used. TippingPoint does not re-sell the vulnerability details or any
exploit code. Instead, upon notifying the affected product vendor,
TippingPoint provides its customers with zero day protection through
its intrusion prevention technology. Explicit details regarding the
specifics of the vulnerability are not exposed to any parties until
an official vendor patch is publicly available. Furthermore, with the
altruistic aim of helping to secure a broader user base, TippingPoint
provides this vulnerability information confidentially to security
vendors (including competitors) who have a vulnerability protection or
mitigation product.

Our vulnerability disclosure policy is available online at:
    http://www.zerodayinitiative.com/advisories/disclosure_policy/

Follow the ZDI on Twitter:
    http://twitter.com/thezdi