ZDI-06-048: Microsoft Internet Explorer normalize() Function Memory Corruption Vulnerability

[zdi-disclosures@xxxxxxxx]

ZDI-06-048: Microsoft Internet Explorer normalize() Function Memory
            Corruption Vulnerability
http://www.zerodayinitiative.com/advisories/ZDI-06-048.html
December 12, 2006

-- CVE ID:
CVE-2006-5581

-- Affected Vendor:
Microsoft

-- Affected Products:
Internet Explorer 6

-- TippingPoint(TM) IPS Customer Protection:
TippingPoint IPS customers have been protected against this
vulnerability since February 27, 2006 by pre-existing Digital Vaccine
protection filter IDs 4163, 3133, 3377. For further product information
on the TippingPoint IPS:

    http://www.tippingpoint.com 

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

The specific vulnerability exists due to improper handling of the
normalize() function. When called in certain circumstances user
controllable memory can be used to execute arbitrary code.

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

    http://www.microsoft.com/technet/security/Bulletin/MS06-072.mspx

-- Disclosure Timeline:
2006.02.27 - Pre-existing digital Vaccine released to TippingPoint 
customers
2006.08.31 - Vulnerability reported to vendor
2006.12.12 - Coordinated public release of advisory

-- Credit:
This vulnerability was discovered by Sam Thomas.

-- 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

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.