Vulnerability Note VU#515749

Microsoft Internet Explorer CSS style element vulnerability

Original Release date: 24 Nov 2009 | Last revised: 27 Nov 2009


Microsoft Internet Explorer (IE) does not safely reference CSS style elements. Using a specially crafted HTML page, an attacker can cause IE to crash and potentially execute arbitrary code.


IE contains a vulnerability in the way it references CSS style elements. Processing a specially crafted HTML page could cause IE to access an invalid memory location and crash. Using heap-spraying techniques, an attacker could leverage the crash to execute arbitrary code.

Please see Microsoft Security Advisory (977981).


By convincing a user to view a specially crafted HTML document (e.g., a web page or an HTML email message), an attacker could execute arbitrary code with the privileges of the user.


A complete solution is not available.

Disable Active scripting

As noted in Microsoft Security Advisory (977981), consider disabling Active Scripting. Instructions for disabling Active scripting can be found in Microsoft Security Advisory (977981 and "Securing Your Web Browser."

Enable DEP

As noted in Microsoft Security Advisory (977981), consider enabling Data Execution Prevention (DEP).

Disabling scripting and enabling DEP do not resolve the vulnerability, but they greatly lower the chances of an attacker being able to execute arbitrary code.

Use Internet Explorer 8

According to Microsoft Security Advisory (977981), Internet Explorer 8 is not affected.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
Microsoft CorporationAffected23 Nov 200924 Nov 2009
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



This vulnerability was publicly disclosed by and/or

This document was written by Art Manion.

Other Information

  • CVE IDs: CVE-2009-3672
  • Date Public: 20 Nov 2009
  • Date First Published: 24 Nov 2009
  • Date Last Updated: 27 Nov 2009
  • Severity Metric: 29.25
  • Document Revision: 15


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