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Microsoft Internet Explorer WMF Image Parsing Memory Corruption Vulnerability

Risk
High

Date Discovered
1/9/2006 12:00:00 AM

Description
Microsoft Internet Explorer is affected by an WMF image parsing memory-corruption vulnerability. This issue is allegedly due to an integer-overflow flaw that leads to corrupted heap memory. This problem presents itself when a user views a malicious WMF-formatted file containing specially crafted data. This issue allows remote attackers to execute arbitrary machine code in the context of the affected application. Failed exploitation attempts likely result in crashing the application.

Symantec Enterprise Security Manager
Symantec Enterprise Security Manager posted an update to the OS Patch Policy that detects and reports systems that are not patched against this vulnerability. Click here for the advisory released February 14, 2006.

Symantec Enterprise Security Manager Network Assessment Module
Symantec Enterprise Security Manager Network Assessment Module detects and reports this vulnerability. Click here for the advisory released April 18, 2006.

Symantec Vulnerability Assessment Symantec Vulnerability Assessment detects and reports this vulnerability. Click here for the advisory released February 15, 2006.

Technologies Affected
Microsoft Internet Explorer 5.0.1 SP4

Recommendations
Permit local access for trusted individuals only. Where possible, use restricted environments and restricted shells.
Do not allow untrusted individuals to have local access to computers. This may limit exposure to local attack vectors.
Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor all network traffic for signs of suspicious or anomalous activity. This may help detect attempts to exploit latent vulnerabilities or malicious activity that occurs as a result of successful exploitation.
Do not accept or execute files from untrusted or unknown sources.
Users should not accept files from untrusted or unknown sources because they may be malicious in nature.
Do not follow links provided by unknown or untrusted sources.
Web users should avoid sites of questionable integrity and never follow links supplied by unknown or untrusted sources.
Do not accept communications that originate from unknown or untrusted sources.
Disabling client support for HTML email may limit exposure to this attack vector.
Implement multiple redundant layers of security.
Since this issue may be leveraged to execute code, we recommend memory-protection schemes, such as non-executable stack/heap configurations and randomly mapped memory segments. This tactic may complicate exploitation of memory-corruption vulnerabilities.

Microsoft has released a security advisory confirming this issue. Users of affected packages should refer to the advisory for further information. Microsoft has released advisory MS06-004 to address this issue. Please see the referenced advisory for further information.
Microsoft Internet Explorer 5.0.1 SP4:

Microsoft Hotfix Cumulative Security Update for Internet Explorer (910620)
http://www.microsoft.com/downloads/details.aspx?FamilyId=C0DF2FC3-2075-46B5-945F-6E0BD6806151

References
Source: [funsec] Another WMF flaw without a Microsoft patch
URL: http://linuxbox.org/pipermail/funsec/2006-January/002828.html

Source: Microsoft Knowledge Base Article 910620
URL: http://support.microsoft.com/kb/910620

Source: Microsoft Security Advisory (913333)
URL: http://www.microsoft.com/technet/security/advisory/913333.mspx

Source: Microsoft Security Bulletin MS06-004
URL: http://www.microsoft.com/technet/security/bulletin/ms06-004.mspx

Source: Technet Security
URL: http://www.microsoft.com/technet/treeview/default.asp?url=/technet/itsolutions/security/default.asp

Credits
Discovered by H D Moore.


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