Vulnerability Note VU#222929
Microsoft Internet Explorer CMarkup use-after-free vulnerability
Microsoft Internet Explorer contains a use-after-free vulnerability, which can allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.
Microsoft Internet Explorer contains a use-after-free vulnerability. This can allow for arbitrary code execution. Internet Explorer versions 6 through 11 are affected.
Note that this vulnerability is being exploited in the wild. Although no Adobe Flash vulnerability appears to be at play here, the Internet Explorer vulnerability is used to corrupt Flash content in a way that allows ASLR to be bypassed via a memory address leak. This is made possible with Internet Explorer because Flash runs within the same process space as the browser. Note that exploitation without the use of Flash may be possible.
By convincing a user to view a specially crafted HTML document (e.g., a web page or an HTML email message or attachment), an attacker may be able to execute arbitrary code.
Apply an update
Use the Microsoft Enhanced Mitigation Experience Toolkit
Important: For this workaround to take effect, you MUST run it from an elevated command prompt.
A dialog box should appear after the command is run to confirm that the un-registration process has succeeded. Click OK to close the dialog box.
For 64-bit Windows systems
Note The following commands must be entered from an elevated command prompt.
A dialog box should appear after each command is run to confirm that the un-registration process has succeeded. Click OK to close the dialog box.
Impact of Workaround: Applications that render VML will no longer do so once vgx.dll has been unregistered.
Note that the vulnerability does not reside in VGX.DLL. This library is used in current exploits, so unregistering it will prevent those specific exploits from working, rather than blocking access to the vulnerability.
Vendor Information (Learn More)
|Vendor||Status||Date Notified||Date Updated|
|Microsoft Corporation||Affected||-||01 May 2014|
CVSS Metrics (Learn More)
This vulnerability was publicly reported by FireEye
This document was written by Will Dormann.
- CVE IDs: CVE-2014-1776
- Date Public: 26 Apr 2014
- Date First Published: 27 Apr 2014
- Date Last Updated: 07 May 2014
- Document Revision: 54
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