Microsoft Internet Explorer Install Engine ActiveX Control Buffer Overflow Vulnerability



Date Discovered

October 12, 2004


A remotely exploitable buffer overflow vulnerability exists in the Microsoft Internet Explorer Install Engine ActiveX control. This vulnerability is caused by insufficient bounds checking of arguments passed to the control leading to a heap overflow. The vulnerability may be exploited to execute arbitrary code in the context of the client user.

Technologies Affected

  • Avaya DefinityOne Media Servers
  • Avaya IP600 Media Servers
  • Avaya Modular Messaging (MSS) 1.1.0
  • Avaya Modular Messaging (MSS) 2.0.0
  • Avaya S3400 Message Application Server
  • Avaya S8100 Media Servers
  • Microsoft Internet Explorer 5.0.1
  • Microsoft Internet Explorer 5.0.1 SP1
  • Microsoft Internet Explorer 5.0.1 SP2
  • Microsoft Internet Explorer 5.0.1 SP3
  • Microsoft Internet Explorer 5.0.1 SP4
  • Microsoft Internet Explorer 5.5
  • Microsoft Internet Explorer 5.5 SP1
  • Microsoft Internet Explorer 5.5 SP2
  • Microsoft Internet Explorer 6.0
  • Microsoft Internet Explorer 6.0 SP1


Run all software as a nonprivileged user with minimal access rights.
Perform all non-administrative activities as an unprivileged user with minimal access rights. This will limit the impact of client-side vulnerabilities.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Exploitation of this and other vulnerabilities may generate suspicious or anomalous network traffic. Deploy network intrusion detection systems to monitor traffic for signs of activity that may indicate exploitation attempts or actions taken as a result of successful exploitation.

Do not follow links provided by unknown or untrusted sources.
Web users should be wary of visiting sites of questionable integrity or following links provided by unfamiliar or untrusted sources.

Set web browser security to disable the execution of script code or active content.
Disable support for client-side scripting and Active Content in the Web browser Internet Zone. This may limit exposure to this and other client-side vulnerabilities.

Implement multiple redundant layers of security.
Deploy memory protection schemes such as non-executable stack/heap configurations and randomly mapped memory segments. This may complicate exploitation of memory corruption vulnerabilities.

Microsoft has released a cumulative update for supported versions of Internet Explorer to address this and other vulnerabilities. Avaya has released an advisory that acknowledges this vulnerability for Avaya products. Customers are advised to follow Microsoft's guidance for applying patches. Please see the referenced Avaya advisory at the following location for further details:



Discovery is credited to Greg Jones of KPMG UK and Peter Winter-Smith of Next Generation Security Software.

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