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CERT Coordination Center

E-Book Systems FlipViewer ActiveX control stack buffer overflows

Vulnerability Note VU#449089

Original Release Date: 2007-06-05 | Last Revised: 2007-06-06


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.


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.


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 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:

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\{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. 

Vendor Information


E-Book Systems Inc. Affected

Notified:  February 21, 2007 Updated: June 06, 2007



Vendor Statement

This issue is addressed in FlipViewer 4.1

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


If you are unable to upgrade, please disable the vulnerable ActiveX control.

If you have feedback, comments, or additional information about this vulnerability, please send us email.

CVSS Metrics

Group Score Vector



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

This document was written by Will Dormann.

Other Information

CVE IDs: CVE-2007-2919
Severity Metric: 0.86
Date Public: 2007-06-05
Date First Published: 2007-06-05
Date Last Updated: 2007-06-06 05:00 UTC
Document Revision: 9

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