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.
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 advisory MS06-004 to address this issue. Please see the referenced advisory for further information. Avaya has released an advisory to identify vulnerable products, and recommends that users apply patches released by Microsoft.