Software Engineering Institute

Logitech VideoCall is video conferencing software for Windows. Logitech VideoCall includes multiple ActiveX controls that contain multiple stack buffer overflows, including the following:

• VibeC (vibecontrol.dll)
• CallManager (StarClient.dll)
• ViewerClient (StarClient.dll)
• ComLink (uicomlink.dll)
• WebCamXMP (wcamxmp.dll)

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 VideoCall ActiveX controls in Internet Explorer

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

{54da0fb5-483a-4c53-810b-f131d50a8eb6}
{6577b09d-c39d-4e22-9913-c99803f9c388}
{917b29f8-e72a-4761-8371-bf7fca27eb31}
{bef0f488-3562-435f-8e89-79d94c9a528c}
{bf4c7b03-f381-4544-9a33-cb6dad2a87cd}
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 these controls:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{54da0fb5-483a-4c53-810b-f131d50a8eb6}]
"Compatibility Flags"=dword:00000400

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{6577b09d-c39d-4e22-9913-c99803f9c388}]
"Compatibility Flags"=dword:00000400

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{917b29f8-e72a-4761-8371-bf7fca27eb31}]
"Compatibility Flags"=dword:00000400

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{bef0f488-3562-435f-8e89-79d94c9a528c}]
"Compatibility Flags"=dword:00000400

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{bf4c7b03-f381-4544-9a33-cb6dad2a87cd}]
"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.