ZDI-07-048: Microsoft Internet Explorer substringData() Heap Overflow

http://www.zerodayinitiative.com/advisories/ZDI-07-048.html
August 14, 2007

-- CVE ID:
CVE-2007-2223
CVE-2007-2224

-- Affected Vendor:
Microsoft

-- Affected Products:
Windows 2000
Windows XP
Windows Server 2003
Windows Vista
Windows Office 2003
Visual Basic 6.0

-- TippingPoint(TM) IPS Customer Protection:
TippingPoint IPS customers have been protected against this vulnerability
since February  8, 2007 by Digital Vaccine protection filter ID 5098. For
further product information on the TippingPoint IPS:

    http://www.tippingpoint.com <http://www.tippingpoint.com/>  

-- Vulnerability Details:
This vulnerability allows remote attackers to execute arbitrary code on
vulnerable installations of various Microsoft software User interaction is
required to exploit this vulnerability in that the target must visit a
malicious page.

The specific flaw exists in the substringData() method available on the
TextNode JavaScript object. When specific parameters are passed to the
method, an integer overflow occurs causing incorrect memory allocation.
If this event occurs after a different ActiveX object has been instantiated,
an exploitable condition is created when the ActiveX object is deallocated
which can result in the execution of arbitrary code.

-- Vendor Response:
Microsoft has issued updates to correct this vulnerability. More details can
be found at:

http://www.microsoft.com/technet/security/bulletin/ms07-042.mspx
http://www.microsoft.com/technet/security/bulletin/ms07-043.mspx

-- Disclosure Timeline:
2006.10.03 - Vulnerability reported to vendor
2007.02.08 - Digital Vaccine released to TippingPoint customers
2007.08.14 - Coordinated public release of advisory

-- Credit:
This vulnerability was discovered by an anonymous researcher.

-- About the Zero Day Initiative (ZDI):
Established by TippingPoint, a division of 3Com, 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 <http://www.zerodayinitiative.com/>

The ZDI is unique in how the acquired vulnerability information is used.
3Com does not re-sell the vulnerability details or any exploit code.
Instead, upon notifying the affected product vendor, 3Com 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, 3Com provides this vulnerability information
confidentially to security vendors (including competitors) who have a
vulnerability protection or mitigation product.