Vulnerability Note VU#449089

E-Book Systems FlipViewer ActiveX control stack buffer overflows

Overview

The E-Book Systems FlipViewer ActiveX control contains multiple stack buffer overflows, which can allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.

I. Description

E-Book Systems FlipViewer is software for viewing "FlipBooks." FlipViewer includes an ActiveX control called FViewerLoading, which is provided by the file FlipViewerX.dll . This ActiveX control contains multiple stack buffer overflow vulnerabilities. Vulnerable properties include UID, Opf, PAGENO, LaunchMode, SubID, BookID, LibraryID, SubURL, and LoadOpf.

II. Impact

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.

III. Solution

Apply an update

This issue is addressed in FlipViewer 4.1. If you are unable to upgrade, please consider the following workarounds

Disable the FlipViewer ActiveX control in Internet Explorer

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

{BA83FD38-CE14-4DA3-BEF5-96050D55F78A}

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_MACHINESOFTWAREMicrosoftInternet ExplorerActiveX Compatibility{BA83FD38-CE14-4DA3-BEF5-96050D55F78A}]
"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 Updated
E-Book Systems Inc.	Vulnerable	5-Jun-2007

References

http://www.cert.org/tech_tips/securing_browser/#Internet_Explorer
http://www.flipviewer.com/download/indexfvenp.php
http://support.microsoft.com/kb/240797

Credit

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

This document was written by Will Dormann.

Other Information

Date Public	06/05/2007
Date First Published	06/05/2007 02:15:58 PM
Date Last Updated	06/05/2007
CERT Advisory
CVE Name	CVE-2007-2919
Metric	0.86
Document Revision	8