Software Engineering Institute

The RIM BlackBerry Application Web Loader is an ActiveX control that is used to load applications onto a BlackBerry device using a PC and Internet Explorer. After the BlackBerry Application Web Loader ActiveX control is used to load software onto a BlackBerry device, the ActiveX control remains on the PC. The ActiveX control is marked "Safe for Scripting" and is scriptable by web pages in any domain. The BlackBerry Application Web Loader ActiveX control, which is provided by AxLoader.ocx or AxLoader.dll, contains stack buffer overflows in the load() and loadJad() methods.

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.

Apply an update

This issue is addressed in Microsoft Security Advisory 960715. This update sets the kill bit for the vulnerable ActiveX control. Developers and web site administrators should install and use the BlackBerry Application Web Loader 1.1 component. Note that installing this package will not register the new ActiveX control on the system automatically. The 1.1 version of the ActiveX control has a different CLSID than the vulnerable version of the control, so it is unaffected by the kill bit that was deployed as part of Microsoft Security Advisory 960715. Please see the BlackBerry Technical Solution KB16248 for more details.

Disable the BlackBerry Application Web Loader ActiveX control in Internet Explorer

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

{4788DE08-3552-49EA-AC8C-233DA52523B9}
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\{4788DE08-3552-49EA-AC8C-233DA52523B9}]
"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.