TUCoPS :: Browsers :: b06-1166.htm

Microsoft Internet Explorer (mshtml.dll) - Remote Code Execution
Microsoft Internet Explorer (mshtml.dll) - Remote Code Execution
Microsoft Internet Explorer (mshtml.dll) - Remote Code Execution

Computer Terrorism  (UK) :: Incident Response Centre

Security Advisory :: CT22-03-2006

Title:			Microsoft Internet Explorer (mshtml.dll) - Remote Code Execution

Organisation:		Computer Terrorism (UK)
Web:			www.computerterrorism.com 
Advisory Date:		22nd March, 2006

Affected Software:		Microsoft Internet Explorer 6.x, IE7 Beta 2
Severity: 			Critical
Impact:			Remote System Access
Solution Status:		** UNPATCHED **

Pursuant to the publication of the aforementioned bug/vulnerability, this document serves as a preliminary Security Advisory for users of Microsoft Internet Explorer version 6 and 7 Beta 2.

Successful exploitation will allow a remote attacker to execute arbitrary code against a fully patched Windows XP system, yielding system access with privileges of the underlying user.


Technical Narrative:
As per the publication, the bug originates from the use of a createTextRange() method, which, under certain circumstances, can lead to an invalid/corrupt table pointer dereference. 
As a result, IE encounters an exception when trying to call a deferenced 32bit address, as highlighted by the following sniplet of code.
Due to the incorrect reference, ECX points to a very remote, non-existent memory location, causing IE to crash (DoS). However, although the location is some what distant, history dictates that a condition of this nature is conducive towards reliable exploitation.
Proof of Concept:
Computer Terrorism (UK) can confirm the production of reliable proof of concept (PoC) for this vulnerability (tested on Windows XP SP2). However, until a patch is developed, we will NOT be publicly disclosing our research.

Temporary Solution:
Users are advised to disable active scripting for non-trusted sites until a patch is released.

Vendor Status:
The Vendor has been informed of all aspects of this new vulnerability (including PoC), but as of the date of the document, this vulnerability is UNPATCHED.

TUCoPS is optimized to look best in Firefox® on a widescreen monitor (1440x900 or better).
Site design & layout copyright © 1986-2024 AOH