IncrediMail IMMenuShellExt ActiveX control stack buffer overflow vulnerability

ID VU:906777
Type cert
Reporter CERT
Modified 2007-04-26T00:00:00



The IncrediMail IMMenuShellExt ActiveX control contains a stack buffer overflow, which can allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.


IncrediMail is an email application that includes animations and 1000's of emoticons. IncrediMail comes with an ActiveX control called IMMenuShellExt, which is provided by the file ImShExt.dll. This ActiveX control contains a stack buffer overflow vulnerability in the DoWebMenuAction() method.


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 with the privileges of the user. The attacker could also cause Internet Explorer (or the program using the WebBrowser control) to crash.


We are currently unaware of a practical solution to this problem. Please consider the following workarounds

Disable the IMMenuShellExt ActiveX control in Internet Explorer

The vulnerable ActiveX control can be disabled in Internet Explorer by setting the kill bit for the following CLSID:

More information about how to set the kill bit is available in Microsoft Support Document 240797. Alternatively, the following text can be saved as a .REG file and imported to set the kill bit for this control:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{F8984111-38B6-11D5-8725-0050DA2761C4}]
"Compatibility Flags"=dword:00000400
Disable ActiveX

Disabling ActiveX controls in the Internet Zone (or any zone used by an attacker) appears to prevent exploitation of this and other ActiveX vulnerabilities. Instructions for disabling ActiveX in the Internet Zone can be found in the "Securing Your Web Browser" document.

Systems Affected

Vendor| Status| Date Notified| Date Updated
IncrediMail Ltd.| | 16 Aug 2006| 04 Apr 2007
If you are a vendor and your product is affected, let us know.

CVSS Metrics

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


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This vulnerability was reported by Will Dormann of CERT/CC.

This document was written by Will Dormann.

Other Information

  • CVE IDs: CVE-2007-1683
  • Date Public: 26 Apr 2007
  • Date First Published: 26 Apr 2007
  • Date Last Updated: 26 Apr 2007
  • Severity Metric: 2.07
  • Document Revision: 12